Hey Red - Golden rule, back up your data - LOL. Computers come and go over the years but the data is the value.
If you are computer literate have a look at "robocopy". This is the Microsoft Robust copy that can be either GUI, or command line and scripted and run from the scheduler or an icon. It has a very good feature (/MIR among many others)of synchronizing files, logical & physical drives etc etc.
I have used other file sync programs and this has been by far the best once setup. I do mine with the command line in a script.