This can and has happened to people who have contacted me for help. Lets look at some ways you can protect yourself from this kind of nightmare. The first and most important step is to make sure there are back up copies of all files on your web site. Having the copies on your hard drive is not adequate, you must have these files backed up on some form of removable object such as diskettes, tape or a zip disk. The hard drive inside your computer does not live for eternity and once it crashes it is usually impossible to retrieve that data.
Age has nothing to do with the survival rate of a hard drive.
You can be sure I was thankful that most of my material was backed up to zip disks. If a large number of sites have links to your site, those links will no longer work. If you are listed in most of the search engines that too will only give your old address. The best way to avoid this problem would be to register a domain name when you first start your web site. If you are unfamiliar with the term domain name, it is simply short address unique to you.