I installed windows 10 preview on my laptop to test it out. After I was done I tried to reinstall windows 8.1 but it won't activate using the key I have. I bought a lenovo with windows 8 (not 8.1) already installed. My product key ends in OEMM How can I install windows 8 or 8.1 and activate it using the key in the bios? I thought I was able to do this in the past?