Follow instructions in this link, ignore the ads at the top.
You can also seek assistance in their malware removal forum, if you choose to follow that path.
McAfee has produced Stinger tools as solutions to help with special threats/infections that are difficult to deal with and we have done so for this threat and are keeping this updated with some of our newer detection signatures and technology that are not yet in the dat files. You can download the FakeAlert Stinger from the following location:
An article is available at http://service.mcafee.com/FAQDocument.aspx?id=TS100893 that discusses this tool as well as instructions for use.
It's best to run it from the Safe mode.
Hope that helps,