Computer always created a recovery partition in the hard disk. which can not be format.
so you need to read your manual that is came with your acer computer and then you need to follow that on your computer. it will fix your computer. If you don't have manual then i am giving you an idea. you just need to follow that idea. then it will make your job easier.
You need to go to BIOS.
and select Boot option (sometimes you will get this option on power also).
once you will select boot option then you will get an option, once you will reach there then you will able to see an option for restore you need to click on that then it will restore your computer.