Check out Microsoft AntiSpyware (meaningful naming :) )
its still a beta version so there are some issues with it. Be careful when deleting any files, sometimes malware names conflict with some legit windows filenames. One such case is the file
This is a legit Server 2003 file, should not be deleted. These issues are already bugged and being fixed. In case of something going wrong, there's a recovery option that might come in useful. ===> I have seen that the recovery option is not fully functional yet .. but its being worked on !