Throw some details on here,.....some else may have the same problem.....there is some very nasty stuff out there.
The exe file: yutnfqcx had embedded itself despite my running the latest versions of ad-aware SE, spybot, AVG anti-virus, and Zone Alarm. I couldn't find it, I KNEW it was running (ctrl-alt-del), but it wouldn't show up when I tried to extract it by 'finding file'...That was UNTIL I found it buried in 'Hidden Files' -- as per the directives at backhoe's post #27.
I simply deleted it, and PRESTO! No more pop-up adware all over the place.