Autosave won’t take the place of regularly saving the file.
It’s designed to try to recover your document if Word crashes, from the last autosaved point. You can set how many minutes Word will to do an autosave, say every ten minutes.
I think the way to turn it on in Word97 is: Click the Tools Menu, select Options, choose the Save Tab, and click the checkbox for Enable Save Autorecover info every ( ) minutes. If not, the method is in Word help.
Word will slow down while it’s saving, so don’t set it for too short an interval... it gets annoying, but it’s better than losing a day’s work.