Vista crashing with yellow pattern on screen

[gfellows]

I'm hoping someone can shed some light on why my PC keeps crashing. Out the blue it started displaying a yellow tarten like pattern on the screen and then rebooted itself. When the safe mode prompt came up there were yellow vertical lines across the screen. I thought that it might have been due to a virus that infected my computer about a week earlier that I sucessful removed.

Just to be safe I did a complete reinstall of vista and everything seemed ok for a while, I used a boot disk to check the RAM and everything checked out ok. However today the same problem just happened the screen went funny with a yellow checkerboard pattern and then rebooted the same as decribed above. I had only just installed the latest nVidia display drivers so I'm thinking that this could be the cause of my problems as the crash report said it was a software error (not that i'm completely sure that it was)

Has anyone had any similar problems or can offer some advice on how I could go about solving this, any help would be greatly appreciated.

[chroma]

Video Board problem.

Open up your PC and remove the entire card, clean all the dust surrounding it.

Check the fans and heatsinks on the card for dust and clean them off.

Reseat the card into the pc (this will ensure it wasnt a seating problem to begin with.

Turn everything back on and see of the cooling fan on the board is rotating (overheating can cause this to happen)
As youve cleaned everything airflow shouldnt be a problem any further so try running it for a while and see if the problem resolves itself.

If it still persists then im afraid its the actual card thats on its way out.