No problem - yeah, you usually want to back up your important files before doing anything drastic like that. If you're hard up for external storage, you can open a Windows Live account and get 20GB of cloud storage for free.
If you just need a word processor, there's always Wordpad that comes with Windows. As long as you don't need to do anything fancy like add pictures or video or anything, it should work. If you need more and you can't get your hands on Word then there are still open source options like OpenOffice.