One final thing, it is VERY important to have all your Windows updates installed and your Windows up to date.
Many of the problems fixed by Windows updates are security updates, and because Microsoft always announce details of the problems they are fixing, many hackers write virues that purposly exploit these security gaps.
It does not matter how good your security software is, if your Windows is not fully up to date you are leaving yourself wide open to some sort of attack.
So set Autiomatic Updates to ON for Windows Updates.