How To: Upgraded to Parallels 5, Got BSOD IRQL_NOT_LESS_OR_EQUAL

Author: erics, Posted November 18th, 2009 at 2:36:06am

After upgrade from Parallels Desktop version 4 to version 5 Windows XP virtual machine fails to boot. IRQL_NOT_LESS_OR_EQUAL Blue Screen of Death is displayed.
Reason: The IRQL_NOT_LESS_OR_EQUAL BSOD (Blue Screen of Death) happens due to multiple CPUs assigned to the virtual machine.
The Fix: Decrease the amount of CPUs to 1:
[code]
Shut down your virtual machine if it is currently running.
Click on Parallels Desktop top menu > Virtual machine > Configure or on Configure button on virtual machine panel.
Switch to General tab and in Processors drop-down list set virtual machine CPU number to 1.
Press OK to save changes and start the virtual machine. This time it should boot normally.
Login and wait while Parallels Tools are being installed.
[/code]
After Parallels Tools are installed, it is safe to return the previous CPU settings.

Categories: How-To's, Technology Tags: bsod, parallels, upgrade, winblows