Because you were infected it's a pretty good guess you have some vulnerability lurking on your system, whether via Java, Flash, Adobe reader Windows and the list goes on, although my money is on Java. I'd format and then just remember to do your updates and keep your 3rd party up to date as well.
I would personally recommend patchmypc. Set it up in the task scheduler with the patchmypc.exe /s option. This way every day patchmypc will run and keep your 3rd party application current and safe. That's how I have mine setup.
I would also recommended keeping your internet activity sandboxed using sandboxie, this is something I also use. .