Windows 7 keeps freezing, need help ASAP!!

Hi all, first off i'm using Windows 7 x86 Ultimate.

2 days ago, i've got these annoying viruses, called something like ICQ Spy Monitor and also PowerSpy 2006.

I don't use ICQ at all but those viruses tell me that they are keyloggers. I've had past experiences with keyloggers and almost had my email & Paypal as well as other important accounts stolen, i had to contact the support to get my account back as their password was changed. Back then, my only solution was to reformat.

But after having been through that before, i now have antivirus and some decent counter measures, i also use Key Scrambler and other programs to encrypt my keystrokes, as well as using Firefox and a few addons that helps encrypts keystrokes, and AI Roboform etc.

But like i said, for some reason i got those viruses again, i haven't been downloading anything at all and don't go to any malicious websites, i only watch Youtube and browse some gaming forums, so i have no idea how i got those viruses.

Anyway here's the main point, I did a virus scan with my antivirus & antispyware programs and they removed them. But I wanted to make sure so i downloaded ComboFix, i think most of you heard of it, it's a very fast and efficient program to remove viruses and fix problems easily, i used that tons for my Windows XP, but it doesn't work on Windows 7 until i found out yesterday that they had a beta released for it. So i downloaded it and tried it, and everything seems to work fine, but now my PC keeps freezing or hang when i open programs or folders.

I'm not sure if it's because i ran Combofix, because it did show a warning message at the start saying that it's only in beta and should not be used on live machines, well i did anyway......

I know the freezing couldn't be the viruses coz my PC ran fine in the past 4 or 5 days and i only found out i got it 2 days ago, it's only after i removed them and used ComboFix that my PC started to freeze.......i'm using 2.5GB of ram so it's not the lag either, my PC runs fine and smooth all the time. The freezing happens randomly, whether if i open a folder or a program, it just hangs there sometimes.

I'm pretty sure it's because of Combofix that altered some system files that caused this problem.



Also, please don't advice me to reformat, if i wanted to i would've done that to fix the virus problems in the first place, but i have too many stuff and have been through a reformat only recently so i'm annoyed and don't wanna go through that again, since everything else worked fine and that i don't really have any important documents or information on my PC that could be stolen, since i deleted them on my PC and backed them up on my USB flashdrive.


edit:

oh and i also tried system restore, it didn't help.