If you need tape drive support and your hardware vendor hasn't produced Vista or Windows 7 drivers you're probably going to be stuck with a dual-boot scenario.
But unless you're running a datacentre, the plumetting cost of hard drive storage has pretty much made tape drives obsolete. And if the manufacturer isn't providing Vista drivers then it seems like your drive really is obsolete.
It sounds to me like the time may have come to migrate your data...
I use a pair of 8GB USB flash drives that I alternate for daily incremental backups to fill in the gap between my full weekly backups. Quick, easy, and if my machine is stolen and I need quick access to my files I can plug them into any computer.
Yes, I do that, too. But I am concerned that with a simple rotating backup one could get both infected with a virus and not have a clean copy to reinstall. Maybe I am splitting hairs here. Hopefully you could clean the USB drive if you knew it was contaminated.
I only do DVD backups monthly - don't want 52 DVDs a year to deal with. Maybe if I had a shredder it would not be so bad.
Re DVD shredding: Do you have a power drill? (How about safety goggles?)
I recently decided I didn't need a bunch of DVD+R backups I'd made about 4-6 years ago, so I took a drill to them! Had them all on a cakebox spindle, held them down with a thick-gloved hand, and the bit went right in. Not only do I imagine that the rough edges and missing chunk would make it really challenging for anyone to get data off it, but the vibration / torque seemed to separate the layers on most of them, leaving the dye layer exposed to the elements. Took only about 10 minutes to do a stack of 50 discs, and that included setup and clean-up.