Hello all, I bought Acer laptop E1-572 which came with windows 8.1 OS. I decided to reformat the hard drive and install windows 7 ultimate x64 version. Now I am thinking about returning the laptop because my wife received one from her sister. Unfortunately, I did not make a recovery media for windows 8.1 OS. Here is my question, I installed RWEverything and found the OEM product key in MSDM. Is this product key for windows 8.1 or windows 7 ultimate that I installed. Thanks in advance!!!