> My parents' computers sometimes did that. It turned out a program called GAIM was responsible. It's some kind of system where you get free software in exchange for ads popping up every 5 seconds, regardless of what programs you are using.

At this point, I'd like to point out that the GAIM you mean is *not* the Gaim instant messaging program at http://gaim.sourceforge.net/ . That software is free, but does not pop up ads.

What you mean is GAIN, the Gator Advertising and Information Network. It's run by a company called Claria (who used to be known as Gator; they changed their name to prevent people associating them with spyware), and any spyware programs you install from them (such as Gator, Gator eWallet, Precision Time, Date Manager, etc) will pop up ads with GAIN.

Sorry, I just had to get that across. The IM client Gaim is one of my favourite open-source programs, and I can assure you now that that wasn't what caused it.