Stop 0x7b On Windows 7

Windows BSOD 0x7B Inaccessible Boot Device

This is an issue I have run into a few times. It can be as simple as allowing Windows to do an automated ‘Startup Repair’, chkdsk/r and/or SFC (offline mode.) But if this is happening because you just cloned or repaired a damaged disk, you may be suffering from a bad HD driver.
The BIOS usually has 3 SATA operating modes: IDE, AHCI or Raid. Each one, in turn, has its own hardware driver within Windows. During initial installation, Windows determines which mode you are using and disables the unused ones.
The trick is to take the unbootable HD out of the original computer and attach it (internally or USB) to a functioning Host computer. Using the Regedit program on the Host, load the SYSTEM hive from the unbootable drive and set the “Start” value to “0” for these three keys:

(Remember, because you are modifying an external hive, HKEY_LOCAL_MACHINE will be replaced by whatever name you provided when loading the external hive. I named the external System Hive HLM in this example.)


Unload the hive from the Host Regedit and the close Regedit. You can then ‘Safely Remove’ the drive and return it to its original computer.
Before letting the system boot into Windows, go into the BIOS and change the SATA operating mode to one of the 2 other modes (I prefer RAID to AHCI or AHCI to Raid) Save the BIOS settings and try booting.

Anytime you clone a drive that uses Intel iaStor drivers, you will likely notice slow (usually bordering on insanely slow) hard drive performance on the newly cloned drive. Re-install the Intel iaStor drivers.

Stop 0xc000021a on Windows 7

Try 1st: Reboot and use F8 menu to start Windows using the ‘Last Known Good Configuration’

Try 2nd: System Restore – keep trying further back in history…the first try might not work

Try 3rd:

  1. Pull HD and plug into a working system (by USB if required)
  2. check the SOFTWARE hive to make sure it is not corrupt. (Load hive into working computer’s registry editor)
  3. If it is corrupt, unload the hive from the registry editor
  4. go to {BadDrive}\System32\Config folder
  5. Rename existing SOFTWARE file to SOFTWARE.BAD
  6. then look into {BadDrive}\System32\Config\RegBack folder
  7. copy the SOFTWARE file into {BadDrive}\System32\Config
  8. Disconnect {BadDrive} and plug back into original system and try booting

Create a Clean BCD File

The following is an except from “Rajan : Computer Blog”
You can find the original post here:
I put it here so I knew were to find it.
It has come in handy recovering more than one “hopeless” situation.

Enter the following commands:

bootrec.exe /fixmbr
X:\boot\bootsect.exe /nt60 all /force

Replace X in the command line above with the device letter to the CD/DVD drive that is running your Windows 7 Recovery Disk.

Now remove the old BCD registry, and create a new one instead.

del C:\boot\bcd

bcdedit /createstore c:\boot\bcd.tmp

bcdedit.exe /store c:\boot\bcd.tmp /create {bootmgr} /d “Windows Boot Manager”

bcdedit.exe /import c:\boot\bcd.tmp

bcdedit.exe /set {bootmgr} device partition=C:

bcdedit.exe /timeout 12

del c:\boot\bcd.tmp

Now we have a clean, working Win 7 bootloader. But we need to add a Win 7 entry to it:

bcdedit.exe /create /d “Windows 7” /application osloader

bcdedit.exe should return a message with a GUID for the newly-created entry. It will look something like this:

The entry {fc8bcc18-8a93-11df-baf9-806e6f6e6963} was successfully created.

You’ll need to use the value that bcdedit.exe returned for you below, along with the drive letter for the drive that Windows 7 is installed to (remember, the GUID listed here is an example, please substitute the one returned to you in the previous command):

bcdedit.exe /set {fc8bcc18-8a93-11df-baf9-806e6f6e6963} device partition=C:

bcdedit.exe /set {fc8bcc18-8a93-11df-baf9-806e6f6e6963} osdevice partition=C:

bcdedit.exe /set {fc8bcc18-8a93-11df-baf9-806e6f6e6963} path \Windows\system32\winload.exe

bcdedit.exe /set {fc8bcc18-8a93-11df-baf9-806e6f6e6963} systemroot \Windows

And, last of all, tell the Windows 7 bootloader to boot the new entry by default:

bcdedit.exe /displayorder {fc8bcc18-8a93-11df-baf9-806e6f6e6963}

bcdedit.exe /default {fc8bcc18-8a93-11df-baf9-806e6f6e6963}

Now the Windows 7 bootloader has been removed and rebuilt from scratch.

At this point, you have a clean and hopefully a fully-working bootloader with one entry for Windows 7.

Reboot your PC system to get back into Windows 7.