From acer's support website....
How to recovery your system from boot-up
1.Locate the Alt key, to the left of the space bar, and F10, on the top row of keys.
2.Power the system on.
3.When the system is powered on, tap the Alt and F10 keys together at the same time when the Acer splash screen appears.
It should state "Please wait a moment..." with the Acer logo in the upper left hand corner.
4.At the eRecovery Management menu it will ask you how to restore.
5.Click on the restore option you would like to use.
If it doesn't work you must have damaged the hard drive, if you buy a hard drive you will need a disc to install windows which doesn't come with the drive.....EXPENSIVE!