On my Windows boot I run:
1. PC Tools Firewall+ because I don't have a router I'm on dialup
2. Avast v5 that is an excellent virus tool both real time and scan by not as good at the other malware very light on resources.
3. PC Tools Spyware Dr. excellent anti malware real time & scan but bogs down my computer.
4. Malware Bytes scan only.
The bogging down is what made me go to Linux. If I disable the real time protection in Spyware Dr. I'm OK. Uncertainty is what will bring me back to Windows. I'm still playing with Linux though.

John
ESI Gigaport HD+
Lenovo Turion II /4 Gig Ram/ Win7x64 be
15.6" Monitor
"The only Band is a Real Band"
www.wintertexaninfo.com/BANDS/JohnnyD.php