Windows : BSOD 0x0000007B [inaccessible boot device]

By | March 2, 2013

If your computer briefly show blue screen “A problem has been detected and Windows has been shut down to prevent any damage to your computer” with stop code “0x0000007B” and then reboot, this usually mean your boot device is inaccessible.

To troubleshoot and hopefully fix this, you need to access the “System Recovery Console” include in your Windows installation disk (boot on disk, and on the next screen click on “Repair computer” at the bottom). You should be automatically be bring to the recovery environment in such case by your Windows installation.

If you are using your installation media to access the Recovery Console, you probably noticed that a Windows partition is detected, but show 0 Mb of space.

Select “Command prompt” and type;

Now you probably see volumes from 0 to 2 (0 is your optical drive, 1 your 100 Mb boot partition and 2 your OS main drive [C:\]).

Under “Ltr” (which mean drive letter), the 100 Mb and your second bigger partition (which is your C drive) are probably missing those letter mount point.

You need to manually allocate the drive letter through diskpart. First, change the current CD/DVDrom letter from D to E :

select volume 0

change letter=E

Then allocate letters to the two partitions :

select volume 1

change letter=C

select volume 2

change letter=D

(you can do “list partition” to see the changes)

exit

Perfect! Now we need to rebuild the Boot Configuration Data (formally known as BCD) :

1. Backup the current BCD

2. Rebuild the BCD

Then it should return the following :

Scanning all disks for Windows installations.

Please wait, since this may take a while…

Successfully scanned Windows installations.
Total identified Windows installations: 1
[1] D:\Windows
Add installation to boot list? Yes<Y>/No<N>/All<A>:

Just hit “Y“.

(in the very beginning, the command “bootrec /RebuildBcd” would have returned :

Total identified Windows installations: 0

Your computer should now boot normally. You might in some circumstances get another BSOD but at reboot, have the opportunity to “boot using last known good configuration” and this should do the trick.