[Help] friend's display is not functioning properly

as i'm typing this post, my friend, and i are trying to fix his computer that is not running properly. he's saying that his display is messed up as in blue lines running down the screen. also, this occurs while running safe mode. but the colors are running normally. he's running at the smallest resolution, and if he goes any higher the screen turns black. as of right now he is running windows normally at lowest resolution, and he also got these error messages:

c:\windows\system32\NvMcTray.dll

c:\windows\system32\nvcpl.dll

c:\windows\system32\nvsvc64.dll (apparently a virus/worm/trojan)

when he boots up the computer, and the boot screen appears; the display is also screwed up. could it be his graphics card or is drivers? or maybe a virus/worm/trojan?

Friend's Computer Specs:

Asus P5K Deluxe (MOBO)
EVGA 8800 Ultra
Intel Quad Core P35 Chipset
4GB RAM
Corsair 600-700W
Windows Vista 64 bit

he downloaded driver sweeper, and is running windows normally, but at a low resolution. he's afraid to make it any bigger, which may cause the screen to turn black again. now he is losing disk space for now reason. he's just sitting there watching his disk space get eaten away. but then it stopped, and he has regained half a GB. also, he is running 2009 kaspersky internet security, and it has detected alerts with MS office (word, excel, etc.) , divx, and real player