Malware Defender is a good product, if you have the time to get everything setup correctly it is more stable then Online Armor and Comodo, bugs are at a minimum and never loses its settings when upgraded
ZOU1 said:Doesn't look like 64 bit is offered.
Might investigate here: http://www.windows7download.com/win7-malware-defender/vepnfomz.html
The last time I used it it made me dizzy