White screen

hey im having an issue where my screen turns white as soon as it logs me into windows.
i can ctrl alt delete and try to open the task manager, but it immediatly goes back to the white screen.
same thing in safe mode.
if i click log out i see the desktop for a fraction of a second, but i cant stop the logout process....
i have the ability to connect the harddrive to my laptop using a sata to usb converter...
i was wondering what would be best to scan the drive with to remove this virus...
im currently trying malwarebytes and spybot....
are there files i should watch for to delete?

i see most the posts asking others to run this or that file while booted off the harddrive, but i cannot launch anything in the background using a run command.

 

so for those who have had the same problem, i fixed it by booting regularly into windows and messing with log in and log off untill i got it to stop part way through. Then i quickly got combofix running. once it did its thing and restarted everything ran well enough to scan the rest of the pc for infection.