same thing happened to me and in the end i had to use my system recovery disk which I was not too happy about. I had adaware on my computer too but it didnt catch it. Try this:
http://www.jwdom.com/blog/attach/200...20/realphx.htm
Its a script that you download and run, it doesnt work all the time because sometimes the files that got downloaded have varied names. Its still worth a try.