DubTrub
If you're worried about the risk of over-writing stuff you want to keep, use CD-Rs. I would be suprised if you managed to fill one of those with the electronic equavalent of your paper docs, even allowing for Windows-bloat. Backup all your data to a new CD each week. Even if you use a new CD
each day you will probably save money against your paper-budget.
This biggest problem, as
curmudgeon point out, is that
One of the problems I've found with data backup is that the default location for each programs data files are all over your hard disc.
This is probably my biggest Windows annoyance -- it's very tricky to cleanly backup everything you need (not strictly relevant, but related, is the issue of MS progs not only storing their data all over the shop, but squirreling their configuration info all over the place as well)