Your TiVo is a desktop computer that uses your TV as a monitor. The Operating System and all your programs are stored on a hard drive.
If the hard drive on your desktop computer crashes, you would replace the hard drive and re-load all the software that came with the computer and that you bought in the first place.
If your TiVo hard drive crashes, all your previously stored programs that had been recorded are gone with the crashed hard drive along with all your recording preferences such as season passes. How do you re-load the TiVo software? You don't. You buy a pre-loaded hard drive and follow their directions that come with the replacement hard drive on how to install the new hard drive. Once the replacement hard drive has been installed, you plug your TiVo back in, re-connect it to the TV and the cable system and re-program it to recognize your cable system and re-program all your preferences all over again.
Here is a link to a company that can supply you with a pre-formatted hard drive for your particular TiVo system: http://www.newreleasesvideo.com/index.php
