Hmmm, one of the other members mentioned this problem being posted more and more...
Our normal fixes don't seem to be working, which makes us think it may be a new problem...
So if you could try a few things for us we might be able to get to the bottom of this...
Could you disable your Mcafee and download Avast or AVG and run a scan (after the scan uninstall the download)
Could you also download Ad-Aware, update it and run a scan...
Cheers, it would be really helpful...
Also what type of files did you download just before this happened...