You can take preventive and post measures to put spyware in it's place. First I'd suggest getting a free program called "Spybot Search and Destroy" this program will scan your system for series of common spyware and help you remove it or contain it. It also runs a residential program sitting quietly in the background using very little system resources until it detects a known suspect.
Second I'd suggest getting another free program called Malaware Anti-Malware scanner. This scanner will delve deep into your files looking for anything that possibly relates to a malicious program and once again assist you in removing or quarantining the rouge programs.
Preventing all spyware is not possible but keeping it well at bay with a few free counter measures is. Also just because these programs are free don't take them lightly they have stood the tests of time.