If you do chose to reinstall and would like to save a little time on backup, perform a clean install without formatting. This will still completely reinstall Windows, but your old installation will be moved to C:/windows.old where you can go and move anything you want over to your new installation (all your personal files, etc). Then you can go into the old program files folder and voila, a complete list of the programs you had, now you can install whichever ones you'd like from an installation source. Once you have finished with that, run Disk Cleanup as an administrator and remove "Previous Windows Installations".
also I'd suggest downloading Microsoft Security Essentials as your AV program and using MalwareBytes on occasion to make...