Helping people with computers... one answer at a time.
It's wise to be prepared to use your backups to fully reinstall your machine in the event of a hard drive failure.
I use Windows XP media center edition, SP3 and have some 18 applications I use regularly. I did not receive original install discs with the PC. I take complete backups regularly, but I'm afraid that if I lose my hard disk, I won't be able to use those backups. I'm really very happy with XP. I don't want to change. What should I do or is there anything I can do to be able to recover from a hardware failure like a disk crash?
In this excerpt from Answercast #12, I address the common situation of having no installation discs for a computer and recommend a complete system image as a safety precaution.
So, good for you for having backups!
What I don't know (and I'm a little concerned based on your statements) is exactly how much you're backing up. If you've been doing true system backups from day one, then those system backups should be able to restore your entire machine.
Let's assume that you're not doing system backups; let's assume you've been backing up only your data:
My recommendation is that you should immediately take a full system image backup of this hardware. This will substitute for installation media in the sense that if your hard disk dies (which is the scenario you're concerned about and rightly so), you can then restore the PC to that disk image on a new hard disk.
You will then be exactly where you were: installed programs and Windows and everything as of the time you took that backup in the first place.
If that's the kind of backup you've already been doing, then I think you're probably in great shape.
Keep the oldest one you can so that you can go back as far in time as possible, if you need to. But for the most part, regular backups, regular system image backups are the way to go and I would suggest that you start doing that as soon as you can.