I bought a notebook Acer V3-771g 6851 with windows 8 installed in it. My doubt is should I enter the windows 8 license key when I reset it to factory settings? I didnt get any windows 8 key with my notebook.
There should be a certificate of authenticity attached to it somewhere, which will have a product key on it. If not, contact the store your purchased it from. You can actually "refresh" your PC through the metro control panel which essentially factory resets without having to enter a product key.
From what I understand, Windows 8 OEM installations do not require a COA label (with key identified) because the actual key is supposed to be embedded in the BIOS so (I'm assuming) there should never be a need (or prompt) for a license key when doing a factory restore.