Now that you've started writing your best-selling novel find an easy way to keep from losing it. Things happen. Computers crash. Files get corrupted. Do yourself a big, huge, gigantic favor. BACK YOUR WORK UP.
It can be as simple as buying a jump drive to keep a second copy of your story on, or you can e-mail the story to yourself, or you can pay for some fancy on-line backup service. Whatever method you use, do it every time you work on your novel. If you don't back it up, you may one day loose all your hard work, and that would be a crying shame--literally.