The simple method is, to format. must you turn on your computer and the infestation is so bad you need to format, only slide a windows xp cd you've either bought or burned into your rom drive, reboot, and go through windows installation. Don't forget to enter your BIOS/CMOS and change your boot sequence so your cd-rom drive boots before your hard drive.

If you've just got a small problem; your computer still runs fine, then you can just clear out your hard drive with any number of programs. I suggest would be Spybot: Search and Destroy, Lava soft ad-aware, and Avast Anti-Virus.

Likely the most user friendly program would be Avast or Ad-aware. Spybot is a little more of an advanced program. It is still one of the best, but if you have trouble understanding computer problems, you might have troubles understanding how Spybot works. Microsoft has also released a new program.

Anyways, once you have one of these programs, start a scan and attempt to remove the infestation. Most of these programs can also plan a boot time scan. This means your computer will reboot and scan before you load windows. This can help remove most infestations because most spyware or viruses can manifest themselves in windows so well that they cannot be deleted unless you delete them before windows loads or from safe mode.