i need a good antivirus badly, my computer is giving me the winlogon.exe error
because of a virus and installing a new winxp didn't fix it.

I like avast. And they have a free version too.

OK, I'll try to download it thank you, but
Any thing else

No, you asked for the best and in my opinion it is the best out there right now.

I prefer AVG, but that's an Opinion.

If you're looking to spend money:

AntiVirus Software Review 2010 - TopTenREVIEWS

That'll show you how they all line up.

Before shelling out a lot of cash, most a/v mfg.'s offer free trials. You can try fully functional programs:


Microsoft antivirus partners

Hope this helps.

I'd go for Kaspersky at the moment. Bit Defender is also very good.
There's a good website that compares antivirus software here:
http://www.antivirusreviewers.com