If you haven't replaced your hard drive in the PC then try the inbuilt recovery manager to restore windows to factory settings.To do that please follow the below instructions.
Note : - Before you start this process make sure no external hard drives are connected to this PC.
Turn On the PC then press Alt + F10 key immediately when you see the Acer start up screen that will show Acer recovery manager from that select restore to factory setting (Out of box condition) then continue with the process.
That will help you restore windows to factory settings.if that doesn't work then you need to get the recovery disc and do the recovery process using that disc.
To boot from recovery disc.
Insert the disc and restart the PC then press F12 key repeatedly when you see the Acer start up screen that will show you boot device menu from that select CD/DVD Rom and press enter.
That will show press any key message immediately press any key on the keyboard and you can boot from the recovery disc and do the restoring process.
I hope the above information helps you.If you have any question please let me know.
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