OK, well not realy OK.

I run an XP on my PC. It's all been going fine untill yesterday evening.

As I think some one managed to dig their way into my PC, not sure how though. At the moment after updating my antivirus software (Avast) and runing AdAware in safe mode, I managed to get rid of the most of the crap on my PC.

the problem is thogh, that something is still blocking autoupdates from switching back on, and I do get an odd window pop up offering me to download an antivirus software.

Any ideas on what might it be and how to get rid of it?