Many of my clients running Windows Operating Systems have questions around Anti-Virus software. The question of which AV is best or how much should I pay for AV come up a lot. Here are a couple of solutions that may help you.
What is most important in this part of the world of computer security is to make sure that your system is up-to-date with the latest security patches for your Operating System and Applications. This is critical to ensure that you avoid being trapped by any broken software. Microsoft supplies automatic updates for their OS and Applications using Microsoft Update. Make sure that you are set to automatically get updated!. Many other applications will check for updates on startup. In addition there are tools to check you system for software that is out of date. One example is Secunia PSI. IT can help and it is free!
Speaking of free; Anti-virus software can be expensive to purchase and some of my clients cannot do that. Check with your internet service provider to see if they offer AV software as part of their service, many do. If not, I would like to suggest that you use Microsoft Security Essentials for your Windows PC. It performs well and does a credible job of protecting your computer.
OH.... You are keeping your data backed up also. Please review my post about CrashPlan for some backup ideas.