[Mobo]

I have seen this before and its actually quite common so lets try what worked for me before:

You will need to boot into the recovery console as seen here:
http://www.techsupersite.com/recovery_console.php

Then at the command prompt type the following line exactly as shown:

copy C:\windows\ServicePackFiles\i386\userinit.exe C:\windows\system32

Then remove the cdrom and type exit to reboot.