Scuba,
It's not wise to archive your footage on your computer. First of all, it takes up space you need for new projects. Second, most likely the drive you have it on is an active drive so you run the risk of losing your archival footage if anything goes wrong while using that drive. Your best bet is to capture (if using tape) or download (if using a drive or solid state cards) your footage uncompressed as your setup will allow and then back it up to an external drive (called a 'client drive' or 'archival drive'.) As a secondary precaution you could save the footage to Blue-ray (DVD is incompatible for archiving HD), but you mentioned that wasn't the way you wanted to go. All you use the client drive for is to download and upload footage. The old-fashioned way is still something to consider. Save a copy of your project to disc and keep your raw footage tapes (if using tape) together. You'll have to recapture unfortunately, but at least you'd be able to fully recover the project.