If you have two computers that you leave on all the time, you can create a simple daily job (I think Windows calls them "scheduled tasks" or something) on computer A to backup it's important files to computer B. And another separate job on computer B to backup it's files to computer A. So it's totally unattended and automatic. Years ago I used to do exactly this using a free program called SyncBack. Get it at http://www.2brightsparks.com/downloads.html - scroll down towards the bottom to get past the paid versions to find the free one. That's probably all you need. Now I have a more sophisticated backup procedure using a Linux server to control things, but that old "A->B, B->A SyncBack" Windows routine worked very well for many years. I didn't sync the entire computers, just the important personal files that couldn't be regenerated by reinstalling the operating system. Documents, photos, music, etc.