Bluscreen after installing wrong driver BOOT_DEVICE_INACCESSIBLE on dual-boot

[Newbie-asker]

Hello!
I have Windows 8.1 and Windows 10 on dual-boot in 2 different partitions
So after installing wrong driver on Windows 8.1 i got boot-loop of bluescreen with error: BOOT_DEVICE_INACCESSIBLE then after few restarts it sends me to screen like this:
http://teamwindows8.com/wp-content/uploads/2012/11/Error-Code-0xc0000001.png
but with message says: "PC failed to start after several restarts so you have to repair it"
i tried boot options and selected safe-mode still no luck and it shows the same error and boot-loop
i tried using my USB installation media repair tools and still no luck , i tried command prompt on the USB recovery tools and it said something like: couldn't identify "which windows installation media"
Please help , i have really important files there
also i tried to set safe mode from msconfig.exe on Windows 10
NOTE: Windows 10 is working fine

 

[LukeFatwalker]

Restart your computer, enter Advanced Boot Options menu, select the Last Known Good Configuration option. If that doesn't work you'll need to re-install the OS.

In the future, you should be backing up your data with a disk imager (i.e. Macrium Reflect) or a snapshot tool (i.e. RollBack Rx).

 

[johnbl]

most likely your drives partitions were reassigned.
you would just boot a windows image and run cmd
and see what your drive assignments are currently set to.
run
diskpart.exe
list volume
(it will show the drive letters and the partitions, make sure your c letter is set to the correct partition)
if it is wrong you can use the assign function to move the drive letters around.
help will show the functions you can use.
exit will exit the program.

sometimes people can just use these commands to do the fix:
bootrec.exe /FixMbr
bootrec.exe /FixBoot
bootrec.exe /ScanOs
bootrec.exe /RebuildBcd

Hello!
I have Windows 8.1 and Windows 10 on dual-boot in 2 different partitions
So after installing wrong driver on Windows 8.1 i got boot-loop of bluescreen with error: BOOT_DEVICE_INACCESSIBLE then after few restarts it sends me to screen like this:
http://teamwindows8.com/wp-content/uploads/2012/11/Error-Code-0xc0000001.png
but with message says: "PC failed to start after several restarts so you have to repair it"
i tried boot options and selected safe-mode still no luck and it shows the same error and boot-loop
i tried using my USB installation media repair tools and still no luck , i tried command prompt on the USB recovery tools and it said something like: couldn't identify "which windows installation media"
Please help , i have really important files there
also i tried to set safe mode from msconfig.exe on Windows 10
NOTE: Windows 10 is working fine

 

[Newbie-asker]

Tried every possible solution on Google includes those in this topic , none worked , much worse , even one of them (assign letter and vol FAT32 one) my Windows 10 stopped working due to boot BCD error , NEVER USE IT ON DUAL BOOT!
i ended up reinstalling Windows 8.1 using a USB stick but luckily didn't lose all my files on Windows 10 HDD
Now i only have Windows 8.1
is there anyway to solve windows 10 boot BCD error?