If my computer is having serious problems like this, I remove the hard drive and attach it as a secondary hard drive of another computer. Then, I boot that computer, and without running any files on the infected hard drive, I'll run virus scans, spyware removal scans, or even just disk integrity scans until I'm satisfied that the problem has been fixed.

Waaah?
Why are you getting so infected?
Stop visiting shady websites!

Get "Spybot - Search & Destroy". It should be pretty thorough in terms of adware/spyware.
For the virus...might I ask what the name, or the symptoms are? (aside from restarting your comp that is)

[img]http://i196.photobucket.com/albums/aa229/azrinirza/makotoshinkai1_zpse3901c5a.gif[/img]
Everyday I'm tumblin'

If it gets really really bad, reformat your computer. Erase everything and start a new one.