virus threat?

Virus never really bothered me with my personal stuff cos I do not have anything important on the PC, except music, and some documents. But It has always made me reinstall the OS, hundreds of times. It has corrupted my OS installation may times that led to the installation, and has now led to the complete non working state of a partition. For sometime, when I had just begun learning computers, I found the repetitive installation process a way to learn to optimize the installation, but as time went on, I found that more boring and later I found that there was nothing I can do about it, but be sure that I have the highest level of security. As years passed by, I was expected to have some important documents stored on my PC, which under no situation should be lost, like my project files, etc. So to get the better of the Virus, I bought a MAC. And from then I didn't have to worry about installing an Anti Virus program on the system and got away from noisy notifications. bourne