I ended up buying a bigger thumb drive but somehow I misread the amount of space I needed and am still short (have almost 6 gigs total)! But I had just enough room on the 2 drives I own to back-up. Hopefully this holiday season will have some good sales since I am going to need to get at least 16g drive. Wish me luck that I don't need them and ended up misplacing one of the drives. Thank you for everyone's input!
@Telsey I was trying to post a reply when I got a warning and here is your post! You still have to have the discs to install the game on your computer. All I am backing up is my current games, downloads from the Sims store and the exchange, screenshots, videos, and other stuff I am not sure what it is. Backing up only protects your current games from your last save before backing up. I am fairly confident this is correct information that I am typing to you. You should have your backup somewhere else then on your computer, copy it to another computer, DVD-roms (which sounds inconvenient), thumb drives, an external hard drive, which ever you choose.