Macrium Reflect is an imaging program. I used to use ShadowProtect, but I now use it at another PC. Macrium images my drive pretty fast and the image size is also pretty small. Around 50% of the normal size if I use normal compression. There is a free version, but also a full version which contains scheduled imaging, differential and incremential images for just 30 dollars. Here is the site: http://www.macrium.com/
Real-time/On-access protection and automatically scheduled weekly on-demand scans: Microsoft Security Essentials Not automatically scheduled periodic on-demand scans: MalwareBytes Anti-Malware I don't know if these are in this category, but I also have: AdBlock Plus/Element Hiding Helper with EasyList subscriptions Ad Muncher Pro WOT for IE/Firefox JavaCool SpywareBlaster
I voted 5+ because you didn't say real time or on demand , so I counted both. Online Armor, Prevx, Sandboxie, SpywareBlaster, SUPERAntiSpyware, Trojan Remover, and Rootkit Unhooker.
Amended, still 5+. I uninstalled Script Defender and replaced it with Wormguard from an old stable of DiamondCS security programs; I use Port Explorer and Wormguard. I started to use ProcessGuard, but decided that I'd use it on another computer here instead of an antivirus. It, and antispyware, and Sandboxie. I also uninstalled SUPERAntiSpyware; it never detected anything. I am paranoid careful. I have a harden system even before I add security apps. ProcessGuard is not for the novice, unless willing to learn.