As a simple way to keep my computer backed up I copy all that I care about onto external hard drives twice a day. I mostly do this in case my internal hard drives would die or something like that, so I haven’t cared too much about finding anything more fancy with incremental history and such. What I have is a simple batch file that I have set to run periodically using the Task Scheduler in Windows.
This is just a little step-by-step guide for how you can open up an open an elevated Command Prompt under Windows 7 (and Windows Vista I think). That is, a Command Prompt with Administrator privileges which allows you to do more stuff than you usually can.