Wipe PC, Keep Selected Files

I'm currently in an architectural design class and it's getting to the time where my teacher likes to get a clean start on the next year computer-wise. Now he always just uninstalls select things and then reinstalls the better versions the next year. Now I was thinking, since these computers are a few years old, he should just format them entirely, speeding them up greatly and clearing out any old problems. And this is where the problem comes in, he wants to save past student's files and I can't think of a way to do this after doing a wipe leaving out the option of backing them up on a seperate drive.