It never hurts to invest in an external drive and back up data regularly or even go for an online backup program like Mozy or Livedrive, you then have relative peace of mind as you can recover past versions etc.

I have an automated disk backup, an automated online backup (with 1.2tb of stuff backed up so far) and a manual clone of my main disk weekly on Sunday evenings.  Overkill perhaps, but I've never lost a thing.

Even using your PCs built in DVD burner (if you have one) to make copies of stuff.  I feel for the poster here, i've had those calls too but I know how to deal with them and if you are not aware of them it must be easy to be sucked in.

Best advice to everybody, backup, backup, backup...you never know...especially these days when photos, videos etc are on your computer, sometimes those memories are worth a few pounds a month in ensuring they are safe.