Here are some free Anti-virus programs and Anti Spyware programs, credit to [sanctified] from neowin.net for the links to these.
Anti-virus
AntiVir - http://www.free-av.com
Avast - http://www.avast.com
AVG - http://www.grisoft.com
ClamWin - http://www.clamwin.com
Anti Spyware
Ad-aware - http://www.lavasoft.de/software/adaware
Bazooka - http://www.kephyr.com/spywarescanner/index.html
Diet K - http://www.dietk.com
SpyBot Search & Destroy - http://spybot.safer-networking.de
SpywareBlaster - http://www.javacoolsoftware.com/spywareblaster.html
SpywareGuard - http://www.wilderssecurity.net/spywareguard.html
WinPatrol - http://www.winpatrol.com/
Feel free to post your own aswell.