I am not sure if I have managed to get rid of GAIN/Gator or just swept it under the rug. What I did was use the System Reset (using XP Home) to a date that I was sure was previous to having GAIN. I was then left with an entry in my program list that referred only to the GAIN website. Ad-Aware found this and deleted it without a problem that I am aware of and the program does seem to be removed. Perhaps someone more knowlegable can tell me if I am correct or if I have just swept the problem under the rug.
