If you are tired with your PC getting virus infected too often here are 2 approaches that have worked for me for a long time.
Things to do before the computer can be marked as “usable” after a clean format
2. Create an user with standard permissions.
3. Start using the computer using the standard permission user. You will get popup screens asking for administrator permission for some task which require admin privileges(This may seem irritating at start, but its worth the deal)
4. Install all standard applications that you would like to be used in the PC.
5. Take a snapshot of your machine using some hard disk imaging software. Macruim reflect works fine for me.
Things to do once you start using your computer
1.Always use the PC with the user with standard permission (created in Step 2 above). This is the most important step.
2. DO NOT download any executable if you don’t trust the source. Actually the best approach would be download all executables from reputed websites like Download.com, since there are less chances of those executables being virus ridden.
3. Always update your antivirus definition updates.