So, I took my hard drive from an HP and put it in my Alienware after my alienware hard drive broke on me. However, the recovery process I went through put windows 7 back on my hard drive but for HP. And now it's telling me my copy of windows is not Genuine. I don't have codes, nor do I have the original disks that came with the Android computer. So, my question is:

How do I erase the hard drive completely and install windows. AND, can I install windows 8 on it instead of 7, which was its original OS? If so, How do I go about doing this? Thank you to all who assist!!