win32/adware virus

Hi.
I have a problem with a virus on my parents computer.
They have Norton Internet Security/Antivirus. The program allert about a virus in C:\WINDOWS\Temp. I checked it and theres .tmp files coming and going all the time. I instaled Nod32 and tried to fix the problem but the .tmp files changing all the time and now i dont know what to do. I googled the problem and all i can fiend is that it's probably toolbar problem. Is there a way to fix the problem without reinstalling the system?
I think there can be one more thing about the problem. My parents has instaled alot of trail games from a site called www.spelspel.se. The problem started when they did that.
Please help me!

Thanks!

 

Hi mats
Welcome to Windowsbbs.

Please download and install HijackThis and Run a scan then close HJT, then run Deckard's System Scanner and post the main.txt log here.
Links and instructions here.

Thanks
Geri