Tracy, in addition to keeping your anti-virus program, up to date,
it is very important to have a back up system.
In my case, having lost all once. I now keep three versions of my back up.
Two on rewritable cd's, and one on a second hard drive.
Every week end I copy the hard drive version to the oldest set of cd's.
Then make a back up to the second hard drive.
I have two back up configs, one for data and one for program files and window, which includes the registry.
Even if I do not get hit by a virus, a good back up can help recover from a bad program install.
And just as important is a firewall.
If your anti-virus program allows it, use the auto update feature.