• After upgrading a Windows virtual machine's virtual hardware to version 7, you may see a blue screen error
• The blue screen error contains the message:
  
  0x0000007B (inaccessible boot device)

This issue is caused by a failure to install the driver for the VMware Virtual disk SCSI Disk Device.

Notes:

• If the virtual machine fails to boot, downgrade the virtual machine hardware. For more information, see Downgrading the virtual machine hardware version (1028019).
  
  If you do not have an option to downgrade the virtual machine hardware, change the SCSI Controller. For more information see Converting a virtual IDE disk to a virtual SCSI disk (1016192).
  
  Once the virtual machine boots, continue with Step 4 provided in this article.
  
  
• You may see other devices in the Device Manager that do not have the correct driver installed.

To resolve this issue:

1. Upgrade VMware Tools, then reboot to confirm that the upgrade is successful.
2. Take snapshot of the virtual machine as a backup.
3. Power off the virtual machine, upgrade the virtual hardware, and power on the virtual machine.
4. Log in to the virtual machine. The drivers in the Device Manager are not installed automatically.
   
   Note: Do not change the driver installation dialogs.
   
   
5. Open Explorer and go to C:\Windows\System32\drivers.
6. Change ownership from TrustedInstaller to Administrators for disk.sys and pci.sys, then add Administrators with Full control permissions to the ACL for these files.
7. Keep the Explorer window open and use a new one to navigate to C:\Windows\inf.
8. Use a third Explorer window to navigate to C:\Windows\System32\DriverStore\FileRepository.
   
   There is a long list of folders there. You need the disk.inf_* and machine.info_* folders.
   
   Note: There may be more than one of these folders . If you do not know which one to choose, select the one with the most recent modified date.
   
   
9. From the disk.inf_* folder, copy disk.inf to C:\Windows\inf.
10. From the disk.inf_* folder, copy disk.sys to C:\Windows\System32\drivers.
11. From the machine.inf_* folder, copy machine.inf to C:\Windows\inf.
12. From the machine.inf_* folder copy pci.sys to C:\Windows\System32\drivers.
13. Locate and install the driver software. Confirm in Device Management that the drivers have been successfully installed.
14. Update the driver for VMware Virtual disk SCSI Disk Device. Browse to C:\Windows\System32\DriverStore\FileRepository for a search including subfolders.
15. Repeat steps 2-15 for the other devices that are listed as Unknown device in the Device Manager.
16. Reboot the virtual machine.