Aargh

any of you two geniuses know why my home page keeps going to a different one. I'm on freeserve and home page always set to open on it, but when I go to Internet Options to clean out cookies and temp files, it's always changed to a different one. A friend gave me a link to Start Page Guard, and I sorted it etc., but when I booted up this morning, it had gone back from freeserve to the other one. Have tried everything I can think of (basically I can sort anything if I sit and take my time) but this has got me really stumped!
I've run virus scans etc., run the Ad aware programme I have but it's still doing it.
Any help appreciated.