this is the file I was referring to. Where is it? That's the reason for all these scans and cleaning tools, and there's nothing there called summer2008.zip.I originally asked you to remove summer2008.zip.
You were asked to disable or remove one of your AntiVirus programs for security purposes, and you refused. Please do so now. Make sure the one use choose to run realtime protection with is fully updated.
Did you look at and try any of the advice on miekiemoes' page for slow computers?
Lastly, you say you're afraid your USB stick might be the culprit? Let's try this, then I will turn you back over to Markka's capable hands.

Download and run this tool with your USB stick plugged in:
http://www.techsuppo...Disinfector.exe
In your reply, please post a new HijackThis log and let us know how your computer is running now.

Regards,
teacup61