Armodeluxe has confirmed my suspicion. He said you have a nasty backdoor infection. So...
Please follow all the directions found
here. After you get to step 5, if your problem is not resolved, post a HijackThis log in the
Malware forum. Be sure to thoroughly describe your current symptoms and what we've done to fix it so far (mainly chkdsk, sfc /scannow, and XP repair). Also give them a link to this topic.
If your problem persists after getting a clean bill of health from a malware expert, return here and we'll continue troubleshooting.

Keep in mind, the malware forum is very busy and can take up to 5 days to receive a reply. There is a special forum called
The Waiting Room if you've been waiting for 3 or more days. You can put a link to your topic & a short description of your problem and someone will get with you soon.
I hope all this mess is from the infection. That way once they're done helping you, it will all be better.

Hope all goes well for you