Develop Bugs

Trying to unlock the bootloader

I get through all the steps, adb setup recognizes my device is connected. When i try to unlock the bootloader <fastboot oem unlock> command line locks up at <waiting for device>.
can someone advise?
Verizon if that matters

What happens when you type in "fastboot devices"

Nothing happens. Tried it both before and after typing in adb reboot bootloader

You sure your pc is detecting the phone when it is in fastboot mode? To me it seems like your computer isn't detecting the phone or the drivers didn't get installed properly.

<deleted>
answered my own question

I had the same issue. Assuming you're using Windows, you need to find where the latest Samsung drivers for the GN were copied to when you installed them (you have installed them, right?) The next time you plug in your phone, it will probably ask you to setup a new device. Tell it you will install the drivers from a location you choose, navigate to the folder where the drivers are, let it install them, restart if it asks, and then try the process over.
FWIW, I used the directions and links from this tutorial and eventually got it working. They include alternate drivers here in case the one from samsung.com doesn't work.

im having the SAME PROBLEM AND HAVE TRIED TWO DIFFERENT COMPUTERS.TRING ADB METHOD

What's the ADB method? Why don't you just just hold the volume up, volume down and power to get into fastboot mode? When you plug it in, windows should see a new device that needs drivers. You need to make sure the drivers are installed before fastboot will work.

i am in fastboot "little android with chest opened". and i do have the driver installed but in fastboot windows thinks its a different device

robitron929 said:
i am in fastboot "little android with chest opened". and i do have the driver installed but in fastboot windows thinks its a different device
Click to expand...
Click to collapse
Is it saying that it couldn't install the drivers for Android 1.0 or something like that? What step are you at? Which tutorial are you using?
Read the driver installation part of this tutorial.
http://forum.xda-developers.com/showthread.php?t=1392310

i got it. it was this
TO GET DRIVER WORKING IN BOOTLOADER YOU MIGHT HAVE TO DO THIS, THIS TOOK ME FOREVER TO FIND!!!!!!!!!!!
I TAKE NO CREDIT!
READ CAREFULLY
THANKS TO KELLEX FROM DROIDLIFE
Tips:
-We know that many of you are running into a “waiting for device” issue when apply the fastboot oem unlock command. This is a driver issue and one that a reader has a suggestion for:
1. Open device manager on your PC.
2. Right click on Android 1.0 with the yellow ! mark on it.
3. Choose update driver.
4. Choose browse my computer.
5. Choose Let me pick from a list.
6. Scroll down and find the Samsung driver with newest date. Should be the driver you downloaded above. (Possibly dated 11/25/2011 ).
7. It will give you a warning about installing the driver, just click yes.

[Q] Enter Fastboot mode with scrapped volume button, to relock the bootloader

Hello friends,
How to get into fastboot to relock the bootloader, if my volume button is dead? By dead, I mean the ribbon has been ripped off of the mobo (it was soldered onto mobo).
Since I'm a brand-new noob, the only way I know of and have done is to get into fastboot mode and lock it back up like what I did when I unlocked it. Any other way to lock it, ideally within the Android OS? Since my volume buttons are completely dead, I doubt that I can get into any "mode" other than OS right now..
TIA!

adb reboot bootloader.

I've seen that command in a post from search earlier, but there was no response after that post.
Would you explain the procedure? I am afraid that I might do anything wrong on top of these disasters i've gone thru with this phone
I also saw another line during earlier search: "if they don't know how to setup an adb command, they probably shouldn't unlock their phones"... Looks like I've done what I shouldn't..?

I would say doing whatever ripped the volume button cable out was what you shouldn't have been doing If you unlocked the phone you have the software you used to unlock, right? What software/guide did you use/follow? Are you using Windows/Linux/Mac? The only way to get to the bootloader w/o the volume buttons (afaik) is to use adb via usb. If you provide more details I can try to help you.

cswithxda said:
I've seen that command in a post from search earlier, but there was no response after that post.
Would you explain the procedure?
Click to expand...
Click to collapse
Once you're in adb reboot bootloader, do fastboot oem lock. Opposite of how you unlocked it in the first place

cswithxda said:
I've seen that command in a post from search earlier, but there was no response after that post.
Would you explain the procedure? I am afraid that I might do anything wrong on top of these disasters i've gone thru with this phone
Click to expand...
Click to collapse
navigate your cmd line to the folder with adb and fastboot in it. Hook the phone up to the computer and type:
Code:
adb reboot bootloader
which will make your phone reboot into the bootloader mode. You can then proceed with what you need to do.
I also saw another line during earlier search: "if they don't know how to setup an adb command, they probably shouldn't unlock their phones"... Looks like I've done what I shouldn't..?
Click to expand...
Click to collapse
I agree with whoever said that. This is another example of people messing with things before reading and learning how they work.

Thanks for your help guys!
btw, anyone found xdadevelopers to load extremely slower in Firefox when compared to Chrome? (just offtopic)
Anyway, I unlocked the bootloader when I was switching to yakju cmd and this folder called "fastboot-and-adb" in which there is both adb.exe and fastboot.exe. I used command "fastboot unlock bootloader" or something alike.
I'll do some more search and learn. Don't want you guys to think of me as a lazy bone who unlocked their bootloader using 1-click toolkit
p.s. edit: in my other thread, someone suggested using quickboot app.
Thanks for your replies guys!

martonikaj said:
navigate your cmd line to the folder with adb and fastboot in it. Hook the phone up to the computer and type:
Code:
adb reboot bootloader
which will make your phone reboot into the bootloader mode. You can then proceed with what you need to do.
I agree with whoever said that. This is another example of people messing with things before reading and learning how they work.
Click to expand...
Click to collapse
Somehow it says device not found
I do have proper driver (Naked Driver Beta 0.5 by 1wayjonny) that my phone was able to be recognized under bootloader at the time when I could actually get into bootloader. My phone is also being recognized as media device now... I have also turning usb debug on...

Try adb remount
The ad devices
This should list the serial number
Then all commands should work
Sent from my Galaxy Nexus using xda premium

cswithxda said:
Somehow it says device not found
I do have proper driver (Naked Driver Beta 0.5 by 1wayjonny) that my phone was able to be recognized under bootloader at the time when I could actually get into bootloader. My phone is also being recognized as media device now... I have also turning usb debug on...
Click to expand...
Click to collapse
You need to turn USB debugging on, and then type "adb devices" and see if it shows up. It may not using the Naked Driver; I had to install the full Samsung USB driver package before ADB would see my Galaxy Nexus.
If it does show up, then you type "adb reboot-bootloader" and it should boot into fastboot. Then just type "fastboot oem lock" and it will wipe the storage partitions and restore the bootloader lock.

Thanks for the help at late night guys. I finally got into the bootloader, thru a mac tho Kinda ironic that I am a supporter of Windows, well, at least a firm user of Windows.
Tried adb remount, it still says device not found
synaesthetic said:
You need to turn USB debugging on, and then type "adb devices" and see if it shows up. It may not using the Naked Driver; I had to install the full Samsung USB driver package before ADB would see my Galaxy Nexus.
If it does show up, then you type "adb reboot-bootloader" and it should boot into fastboot. Then just type "fastboot oem lock" and it will wipe the storage partitions and restore the bootloader lock.
Click to expand...
Click to collapse
I believe that you quoted my "I have turned USB debug on" ;p
Gave up on trying Windows drivers. When I was flashing the Yakju, I tried Samsung full driver, and it didn't work on my machine, i.e., the phone can't be detected in bootloader mode, while the beta 0.5 driver worked. So I decided not to mess with it anymore.
It looks like when the phone is not under bootloader, windows recognize it fine as MTP devices and install proper samsung driver from the internet directly. This allows me to open it up in explorer to browse files and such, but the phone won't show up under adb devices somehow.
Looks like MTP device (when the phone is in Android OS) and the fastboot mode use two kinds of drivers. This is just my assumption, though.
Anyway, finally got into bootloader now with Mac, and it's pretty funny I have to do everything thru command as the volume rockers are dead
And most importantly, thank you guys for your help!

Just another update
It's real funny now that the bootloader is locked, I can't unlock it again cuz I don't have the volume button working, so I couldn't choose YES on the phone.
I'm not trying to unlock it again, but just to confirm if there's really no work around, in case I encounter this situation again in the future
Lucky that locking the bootloader won't erase everything, or I won't be able to flash a ROM with it locked... :cold sweating:

fastboot mode not working

hi everyone, i'm trying to install CM9 on my LT15i, i've tried using the CM wiki instructions and both the following guides...
androidauthority.com/xperia-arc-lt15i-root-android-4-0-ics-80265/
and
androidforums.com/rezound-all-things-root/506466-scottys-noob-friendly-root-guide-start-finish.html
the phone is already fully unlocked and has CM 7.2.0 anzu installed. i've tried simply using the clockwork recovery mod bootloader to wipe the phone and install CM 9.0.0, but on reboot the phone gets past the boot logo then just shows a black screen, so i assumed i needed to flash an appropriate ROM for CM9; this is where my problem begins.
every forum i've read about this process says i must enable usb debugging (done) and "disable fastboot" under settings>power, i do not have a "power" option in my settings and cannot find anything related to fastboot on the phone; although i'm not sure this is the problem. when android is running normally and i attempt to list devices with adb.exe on windows, it successfully returns the phone's serial number. when i shut the phone down, hold the menu button and plug in the usb cable, fastboot mode appears to work correctly as the LED comes on blue and "android adb device" appears in the windows device manager (i've tried installing the arc usb/adb drivers from various sources, they all seem to work correctly). but when i attempt to list devices after restarting in fastboot mode, adb.exe says it cannot find any device. fastboot.exe has not communicated with the device whatsoever, but i assumed i might need to get the adb.exe usb daemon/server running correctly first for this to work.
i did this process once already when i installed CM7, it was successful the first time and everything went smoothly. from what i recall i just did exactly as described above and fastboot.exe was able to find the device no problem. but that was a number of months ago, hopefully i'm just missing some obvious step.
cheers

WookieInHeat said:
every forum i've read about this process says i must enable usb debugging (done) and "disable fastboot" under settings>power, i do not have a "power" option in my settings and cannot find anything related to fastboot on the phone;
Click to expand...
Click to collapse
There is no such thing. And USB debugging is only required if you want to root stock ROM, every other action can be done without it.
WookieInHeat said:
although i'm not sure this is the problem. when android is running normally and i attempt to list devices with adb.exe on windows, it successfully returns the phone's serial number. when i shut the phone down, hold the menu button and plug in the usb cable, fastboot mode appears to work correctly as the LED comes on blue and "android adb device" appears in the windows device manager (i've tried installing the arc usb/adb drivers from various sources, they all seem to work correctly). but when i attempt to list devices after restarting in fastboot mode, adb.exe says it cannot find any device. fastboot.exe has not communicated with the device whatsoever, but i assumed i might need to get the adb.exe usb daemon/server running correctly first for this to work.
i did this process once already when i installed CM7, it was successful the first time and everything went smoothly. from what i recall i just did exactly as described above and fastboot.exe was able to find the device no problem. but that was a number of months ago, hopefully i'm just missing some obvious step.
cheers
Click to expand...
Click to collapse
Drivers, drivers, drivers.
If your phone is in fastboot mode, make sure drivers are installed. Proper drivers.
You do not need ADB server for installing a kernel.
Just open up Command Prompt and install the kernel with command
Code:
fastboot flash boot boot.img
.
Assuming boot.img is in the same folder as fastboot.exe.

Someguyfromhell said:
Drivers, drivers, drivers.
If your phone is in fastboot mode, make sure drivers are installed. Proper drivers.
Click to expand...
Click to collapse
thanks for the reply someguyfromhell. i've tried every "android adb interface" driver under the sun for the S1 fast boot device that appears in the windows device manager when i put the phone in fastboot. when i try to send any command with fastboot.exe it just hangs at "waiting for device", i've fiddled with this stuff every which way and just cannot get fastboot.exe to see the phone. i've tried switching up the usb ports on this computer, but haven't had the opportunity to try a second computer. you've let me know i'm going in the right direction at least, if i have the same results on a second machine i'll pursue the issue further.
thanks again
wookie

WookieInHeat said:
thanks for the reply someguyfromhell. i've tried every "android adb interface" driver under the sun for the S1 fast boot device that appears in the windows device manager when i put the phone in fastboot. when i try to send any command with fastboot.exe it just hangs at "waiting for device", i've fiddled with this stuff every which way and just cannot get fastboot.exe to see the phone. i've tried switching up the usb ports on this computer, but haven't had the opportunity to try a second computer. you've let me know i'm going in the right direction at least, if i have the same results on a second machine i'll pursue the issue further.
thanks again
wookie
Click to expand...
Click to collapse
You need to unlock bootloader, if you want to install CM ROM. Arc S can only have bootloader unlocked via official method, there you can also download the correct driver which you need.
http://unlockbootloader.sonymobile.com/

Someguyfromhell said:
You need to unlock bootloader, if you want to install CM ROM. Arc S can only have bootloader unlocked via official method, there you can also download the correct driver which you need.
the bootloader is already unlocked, as i said, the phone has CM7 on it currently.
Click to expand...
Click to collapse

[Q] Problems in adb/fastboot

Hey all,
I've been rooting phones for a little bit, so when I got my Nexus 7 a couple weeks ago and found that it was as simple as "fastboot oem unlock", I was thrilled. However, it ended up not being that simple, of course.
At first I couldn't get the device to show up for ADB or fastboot at all, even though Windows recognized the device. I downloaded the zip file of the drivers from Google, no luck. Downloaded a new version of the Android SDK, and used the adb/fastboot from it, and then ADB was able to see the N7 and was able to reboot it into the bootloader. However, once in the bootloader, it stops recognizing that the N7 is connected again. Trying "fastboot oem unlock" just causes the program to display <waiting for device> indefinitely.
So that's where I'm stuck now, I haven't been able to find any concrete details on this that are for the N7 2013 (pretty much everything I've found has either not been helpful or has been related to the original N7). Anyone able to help from here? Thanks!

Do u have USB debugging enabled in developer settings? Try turning your USB computer connection to PTP from MTP if you haven't already in storage settings. Then a pop-up will come on your n7 asking to approve your computer to see it. Tell it yes
>^.^< Sent From Meow HTC One

DowntownJeffBrown said:
Do u have USB debugging enabled in developer settings? Try turning your USB computer connection to PTP from MTP if you haven't already in storage settings. Then a pop-up will come on your n7 asking to approve your computer to see it. Tell it yes
>^.^< Sent From Meow HTC One
Click to expand...
Click to collapse
Thanks for the suggestions. Alas, I tried these things. The problem exists now when I'm in the bootloader, which is where fastboot won't recognize that the device is attached.

tigerxchaos said:
Thanks for the suggestions. Alas, I tried these things. The problem exists now when I'm in the bootloader, which is where fastboot won't recognize that the device is attached.
Click to expand...
Click to collapse
When you have the device connected to your computer when it's at the Bootloader screen, what does Device Manager show on your computer? Does it recognize the tablet but doesn't know what it is? You may need to install the drivers when you have the device in the Bootloader menu. I use the Google USB Driver (which you can download in the SDK Manager), right click on the device in Device Manager, select "Update Driver Software", "Browse my computer for driver software", "Let me pick from a list of device drivers on my computer", then browse the list. It may be listed under Android Device, Google...just look down the list, then select the appropriate driver. I believe from there you can select "Android Bootloader Interface", and that should let fastboot commands work.
You may need to reboot the computer.

Make sure you are using the usb cable that came from asus.

Thanks for the help. I tried the process again on a different computer, and eventually got it to work. I was able to unlock bootloader and flash TWRP 2.6.3.0. However, I was only able to mount System, Cache, and USB-OTG as partitions in TWRP, so I couldn't figure out where to drop the SuperSU binary .zip file. I tried rebooting, and (this may have been a mistake) installed the TWRP SU binaries on the way out. Now the device is stuck in a bootloop. Not sure if it was related to the SU binaries or the fact that I couldn't load any sort of data partition. Any thoughts?
EDIT: Apparently the root instructions don't make it clear that you will lock your data partition if you don't boot the device after unlocking the bootloader. I went straight into TWRP from the bootloader after unlocking it, and got a password request. Hit "Cancel" and it let me into TWRP, but factory reset failed. I had to wipe data, wipe cache, then reboot, then do a factory reset and now I'm back in.

Unable to get xA2 in fastboot mode

Hi there,
strugggling to get the xa2 into fastboot mode so I can flash a new boot.img and root. I've enabled OEM unlocking and installed the USB drivers. the command 'adb reboot fastboot' doesn't work, just reboots the phone. adb over usb works fine. The official method to get into fastboot 'plug in USB whilst holding vol up/down' also doesnt allow me to get itno fastboot mode, phone just stays blank with a notification LED. I use 'fastboot devices' to see it if it connected. I've tried this on 2 PCs now to no avail
I'm thinking maybe the fastboot drivers are wrong?
Does anyone have any other suggestions or help?
Thanks

jaw2floor said:
Hi there,
strugggling to get the xa2 into fastboot mode so I can flash a new boot.img and root. I've enabled OEM unlocking and installed the USB drivers. the command 'adb reboot fastboot' doesn't work, just reboots the phone. adb over usb works fine. The official method to get into fastboot 'plug in USB whilst holding vol up/down' also doesnt allow me to get itno fastboot mode, phone just stays blank with a notification LED. I use 'fastboot devices' to see it if it connected. I've tried this on 2 PCs now to no avail
I'm thinking maybe the fastboot drivers are wrong?
Does anyone have any other suggestions or help?
Thanks
Click to expand...
Click to collapse
Hi
Install "5 seconds adb drivers"
Connect the turned off phone to PC via USB just pressing volume down button (no power) and keep pressing it until you see the LED turning green or blue.
Here u have! :highfive:

faby GT said:
Hi
Install "5 seconds adb drivers"
Connect the turned off phone to PC via USB just pressing volume down button (no power) and keep pressing it until you see the LED turning green or blue.
Here u have! :highfive:
Click to expand...
Click to collapse
Hi thanks for getting back to me,
I assume you meant the '15 second installer', which I just did just install successfully. I am still unable to see the device with 'fastboot devices' command.
Other info: I have factory reset the phone, made sure oem unlock is checked, tried the same process on another computer. I can get adb mode to work fine, but the command 'adb reboot fastboot' just reboots the phone as usual

jaw2floor said:
The official method to get into fastboot 'plug in USB whilst holding vol up/down' also doesnt allow me to get itno fastboot mode, phone just stays blank with a notification LED.
Click to expand...
Click to collapse
That is the correct behaviour.
Blue LED = Fastboot mode
Green LED = Flash mode (for reflashing stock firmware with XperiFirm in case EVERYTHING is broken)
Install these drivers:
https://adb.clockworkmod.com/
When in Fastboot mode, go to device manager, there is an Android device in there (may also be called MTP device).
In the device manager, install a new driver for that and use the ADB driver from C:\Program Files (x86)\ClockworkMod\Universal ADB Driver
Windows will tell you that it's the wrong driver. Install it anyway and Fastboot will recognize your XA2 now.

schmatzler said:
That is the correct behaviour.
Blue LED = Fastboot mode
Green LED = Flash mode (for reflashing stock firmware with XperiFirm in case EVERYTHING is broken)
Install these drivers:
https://adb.clockworkmod.com/
When in Fastboot mode, go to device manager, there is an Android device in there (may also be called MTP device).
In the device manager, install a new driver for that and use the ADB driver from C:\Program Files (x86)\ClockworkMod\Universal ADB Driver
Windows will tell you that it's the wrong driver. Install it anyway and Fastboot will recognize your XA2 now.
Click to expand...
Click to collapse
If it won't work, after that just go to devices and printers and delete Xperia XA2. It will work.
Else, after installing 15 seconds, inside device manager, update the driver of your phone (or mtp device), select local, then Android device, then fastboot. Disconnect the phone and reconnect as before (volume down)

Fastboot is VOL. UP (on this device)! (Not vol. down)
So basically turn off the device, hold Vol. UP and simply connect to USB, hold Vol. UP until LED is steady blue and you are set.
Note: VOLUME UP activates fastboot and VOLUME DOWN enables flashmode and/or recovery mode

Similar trouble here.
1. VOL UP + plug in USB: Blue led blinks once, then phone shows it's charging (turned off)
2. adb reboot bootloader: Phone just turns off

Corias said:
Similar trouble here.
1. VOL UP + plug in USB: Blue led blinks once, then phone shows it's charging (turned off)
2. adb reboot bootloader: Phone just turns off
Click to expand...
Click to collapse
I had the same issue with my XA2.
The solution (at least for me) was: different USB cable and different USB-port. As it turns out, my cable was somehow worn out (though data transfer and charging was working quite well). Going into fastboot, the blue led lit very short time and then the phone restarted. Furthermore on my PC it somehow only worked on the one USB port and not the other (both USB 3.0).
--> Maybe trying the most obvious might help also some of you

BoernMe said:
I had the same issue with my XA2.
The solution (at least for me) was: different USB cable and different USB-port. As it turns out, my cable was somehow worn out (though data transfer and charging was working quite well). Going into fastboot, the blue led lit very short time and then the phone restarted. Furthermore on my PC it somehow only worked on the one USB port and not the other (both USB 3.0).
--> Maybe trying the most obvious might help also some of you
Click to expand...
Click to collapse
Did solve this by connecting to different PC. No cable/port/hub change did help. Looks like there was some trouble with drivers (though the same PC fastboots Z3 Tablet Compact perfectly).

Same
I'm also having the same issue with my Xperia XA2 Ultra. (boy that's a mouthful)
Phone model is H3223.
Host OS is Windows 10 Pro v. 2004.
Using latest Android SDK tools (i.e. ADB and Fastboot platform tools): platform-tools_r30.0.5-windows. Got it directly from Android site.
I think I had a previous driver for Android already installed or somehow Windows got it. ADB worked, Fastboot didn't. Read online about someone on this forum getting it to work by using XZ2 driver from Sony as they evidently don't have a published driver for this device. The person who posted this solution had reported problems with this driver recently. I tried it anyway.... ADB commands work and my phone shows up when listing devices. Reboot into fastboot mode and the only thing my phone does is show a blue light indicator... no splash screen or logo. To me this means it's starting fastboot but my driver isn't working with it to recognize it as any commands for fastboot return nothing or fail. It doesn't show up under fastboot devices command.
Does anyone have a clue as to what to do?

that_random_guy said:
Same
I'm also having the same issue with my Xperia XA2 Ultra. (boy that's a mouthful)
Phone model is H3223.
Host OS is Windows 10 Pro v. 2004.
Using latest Android SDK tools (i.e. ADB and Fastboot platform tools): platform-tools_r30.0.5-windows. Got it directly from Android site.
I think I had a previous driver for Android already installed or somehow Windows got it. ADB worked, Fastboot didn't. Read online about someone on this forum getting it to work by using XZ2 driver from Sony as they evidently don't have a published driver for this device. The person who posted this solution had reported problems with this driver recently. I tried it anyway.... ADB commands work and my phone shows up when listing devices. Reboot into fastboot mode and the only thing my phone does is show a blue light indicator... no splash screen or logo. To me this means it's starting fastboot but my driver isn't working with it to recognize it as any commands for fastboot return nothing or fail. It doesn't show up under fastboot devices command.
Does anyone have a clue as to what to do?
Click to expand...
Click to collapse
I have the exact same problem, have not managed to find a solution trying with 3(!) different laptops and 2 different cables. No idea what could go wrong. I checked the device and it says that unlocking is okay. Really frustrating.
Edit: I actually found a way! Once you manage to enter the fastboot mode (light is permanently blue) go to the device manager in windows, click on the unknown android device, and install custom drivers (either by selecting from the list or by picking the universal adb driers from a local folder). These custom drivers should be adb drivers. Once they are installed, fastboot should work.

I had the same problems with my device XA2 H3113 and Win10.
My solution: Try it with Ubuntu. Just grab an 8GB usbstick, install Ubuntu via usb-installer, boot ubuntu and open a terminal
sudo apt update
sudo apt install adb fastboot

LolRoll said:
I have the exact same problem, have not managed to find a solution trying with 3(!) different laptops and 2 different cables. No idea what could go wrong. I checked the device and it says that unlocking is okay. Really frustrating.
Edit: I actually found a way! Once you manage to enter the fastboot mode (light is permanently blue) go to the device manager in windows, click on the unknown android device, and install custom drivers (either by selecting from the list or by picking the universal adb driers from a local folder). These custom drivers should be adb drivers. Once they are installed, fastboot should work.
Click to expand...
Click to collapse
Hey can you please provide me a link to the drivers? as I've been trying so many drivers and they don't work.

LolRoll said:
I have the exact same problem, have not managed to find a solution trying with 3(!) different laptops and 2 different cables. No idea what could go wrong. I checked the device and it says that unlocking is okay. Really frustrating.
Edit: I actually found a way! Once you manage to enter the fastboot mode (light is permanently blue) go to the device manager in windows, click on the unknown android device, and install custom drivers (either by selecting from the list or by picking the universal adb driers from a local folder). These custom drivers should be adb drivers. Once they are installed, fastboot should work.
Click to expand...
Click to collapse
works for me