Need some help here

I have a win7 with a 500 gb 5400 rpm hdd. Now, I need a solution that makes
sure I can conveniently get back data no matter what. Incase virus /
malware infects me external hdds are out. With antiviruses, there is
no assurance. Data lost is lost. Plus it slows down the pc. My data
is also precious to me. I was thinking the answer is a recovery
solution. I think Rollback Rx is a good recovery tool. I think its
convenient to use. What do you say? Do you have suggestions other
than it? I was given the name by a friend whose opinions i respect in
such matters