XP freezing problem

[OlIv0rIolI]

A few days ago on April 1st, my computer would freezes up randomly. It began when I was browsing in Firefox. First my anit-virus AVIRA shows a message saying somekind of virus infection(I forgot the name of it), then browser stops working, then after I click on the start up bar it would freeze too. ctrl-alt don't work. I had to push restart button. after startup I ran antivirus while playing CIV game. And then later everytime I open Firefox, after a while it would freeze xp. sometimes just letting it sit there it would freeze xp on its own.

At first I thought it was firefox, I reinstalled same results. Later after many restarts, I decided to watch an epside of a show and after a little while, the media player would freeze the system as well.

Azuerus Vuze also freezes xp a minute after startup.

Its not a heating problem. I ran memory test, everything is fine. I run malwarebytes, shows some viruses. I don't see any virus after the scan. I decided to switch to internet explorer 8 and internet is working fine now. Any help is appreciated

Oh I am thinking of running a program called RegCure. I read somewhere online that xp freezing could be caused by registry problems. Is the program legit? Any help to solve this freezing problem would be appreciated

My specs are
intel q6600,
4gb of ram,
gigabyte dq6 motherboard,
7900gs,
320gb hd separated into 80gb(xp), 60gb(vista), 20gb, 160gb
500gb hd empty for now
4tb raid array with random stuff

 

[OlIv0rIolI]

I decided to reformat, but I have some questions.

I have 4 partitions on one hd. THere are for C:XP, D:Vista, and 2 storage. When I am using xp, C drive is primary and the other 3 are extended partitions. When I am using Vista, that drive automatically switches with XP drive: So Vista is now C drive and XP is now D drive and labeled as extended partiton. If I reformat XP, will it mess with this setup? and are the information stored on the storage drives be affected?

Also I have Areca PCI RAID Hardware with a raid5 setup with 4 1tb drives. Are the information on this drive safe?