When you first turn a new pc on it prompts you to create a set of recovery disks, many don't bother and may finish up having to pay for a set from Acer or whoever made it.
Later model Acer's make a seperate recovery disk for drivers and programs. If you have to do a full restore to factory settings you will loose all your data.
So the first thing to find out the precise message "missin or corrupt" is a bit vague, get an accurate error message.