PA.
I would think your "Recovery Disk" would restore your system to "as new" state. Generally all you need to do is set the Bios to boot from CD (this may be already done), stick the CD in and reboot.
Hopefully, after the associated dire warnings of "all info on your hard drive etc etc" installation will then take place.
Another disaster plan is to buy another hard drive NOW, stick it in as a slave, copy everything from the original, and then REMOVE it. This then gives you a snapshot which you can be confident in if the HDD grind to a halt.
Then every 3 or 6 months repeat the drill. Hopefully the hard drive doesn't crash during one of these copy sessions
MAx