Thank you for your suggestion, sarcastic icon and all. I'm aware of the frustration the helpers on this forum must feel when the same questions keep popping up, which is why I keep up to date with all threads as they happen.
I have Ad-aware installed, and have quarantined all the files it suggested; the popup I described is still happening. As I mentioned elsewhere in this forum, just being told to remove anything that looks as if it shouldn't be there often doesn't help the non-expert. I found carpserv.exe on both msconfig and in the Registry. Should it be there or not? How would I know? Msupdate.exe is not the sort of file the non-guru would risk removing. Should I?
My question in fact was whether there was any correlation between the worm I mentioned and the popup, not how do I remove the popup.
P.S. The link you posted also suggests removing Messenger, which I'm sure will be very effective in removing popups that target Messenger, but it seems a rather drastic step for somebody like me who uses Messenger every day.