I have a 1TB drive in my computer dedicated to backups, mine, Purple's, and our daughter's computers backup each night to it.
I made 3 shared folders on the "backup" drive and made a "base" backup of each system, then schedule a differential backup for Sunday through Saturday for each(it only gives me 7 days of "recent" backups, otherwise I have to go back to the orginal "base" backup). With a larger drive I could do weekly & monthly backups (what I really should be doing).
The 3 computers are all Windows 7, 64 bit on a windows home network.