Hello and welcome to bleepingcomputer!
I read about your problem and have the following suggestions.
First open your computer and ground yourself to the case by placing your hand on the metal enclosure. This nuturalizes static electricity.
Remove the power plug from the power supply.
Remove the monitor plug from the video card, then remove the video card from its slot.
Re-insert the video card into the slot again and make sure it is firmly seated evenly accross the slot and locked in if it is an PCI-E or AGP card.
Return the monitor plug into the video port, make sure it is fully in place and tight.
Check the inside of the computer for dust or lint build-up, if you witness any, I suggest you try removing this dust as best as you can. Some people use compressed air in a can to do this.
Next return the plug to the power supply and power up the computer.
Please observe the inside of the computer for all fans spining.
close the case.
Since you mentioned malware, you may have deleted some files or drivers that were needed for the system to run properly.
Go down the list of hardware, like motherboard chip-set drivers, video card drivers, make sure those are all updated.
Check your device manager to make sure it is not displaying any exclamation marks or X's. If you see any, that is an inidaction you are missing that hardwares drivers.
Good luck and please post back how things have gone.
Edited by MrBruce1959, 25 June 2010 - 10:49 PM.