Spybot and Adaware will clean up 99% of spyware, adware, and malware, www.cexx.org is a good source of information on these "exploitive" apps.
You can also get a good free virus scan at http://www.housecall.antivirus.com (trendmicro)
and www.pspl.com (proland) is another good virus information site and free scanner, along with the better known www.symantec.com and www.mcafee.com. I personally believe you can't be too protected these days....