This is the way I protect my PC and I have never ever encountered any problems for a year now. I am using Windows 7 just to let you know. Antivirus - Microsoft Security Essentials Firewall - Comodo Firewall - its just bit annoying with its pop ups but it is its purpose warning you of whats coming in and out in order for you to accept it or deny it. Shadow Defender - software like deep freeze where you have your PC in a deep freeze state. Everytime you restart your computer it all goes back to the previous state where you have turned on shadow mode. The best thing with these compared to deep freeze is it already has the feature to exclude folders you dont want to be in shadow mode. Thats it. Those are the 3 Softwares that does protect my PC.