Dear
Couple months i purchased Dell Inspiron 15r 5537 with Windows 8.1 Single language. Two weeks ago my windows crushed, and the computer stops to boot, then i tried different solutions. at last i install got windows 8 pro cd, and i installed, and my all files got (windows.old). I don't remember my Microsoft OEM product key, and i can't restore my original windows 8.1 to my laptop. My question is how could i restore my original OS factory from recovery partition.