Try looking for an Acer e-Recovery Management application in the Acer folder. If it's there, you should be able to restore the laptop back to factory condition.
Another thing you can try is to open the My Computer window, then right-click on the hard drive, and left-click on Properties in the right-click drop-down menu. Left-click on the Hardware tab in the Properties window, and highlight the hard drive in the tab. Left-click on the Properties button in the lower right-hand part of the tab. This will open a new window that shows the properties of the actual hard drive in your computer. Left-click on the Volumes tab near the top of this window, then left-click on the Populate button in the lower right section of the tab. If it shows a partition with no drive letter assigned to it, that is the hidden partition on the laptop.