There is a lot on it click here but how to cure it appears a bit muddled as you say.
I suggest you run your anti-malware scanners and see if they pick anything up; make certain they are updated first. You could also try an online scan like Trend Micro HouseCall click here and a cleanup with the likes of Ccleaner click here make certain it is the latest version.
If the problem persists download Hijack This click here and post a copy of the file here click here in the English Forums (marked as English-Help) or here click here. You will need to register with the Forum before you can post.
Hope this helps.