So a while back I bought a used gaming computer (specs: http://pcpartpicker.com/user/MrBeastshaw/saved/2uWw). It has W7 Ultimate 64 bit installed on the OS but the guy I bought it from never supplied my with the COA. When I asked it from him originally he said he didn't want me to have his info but if I needed to do a clean install just to bring the PC to him. Instead I used a product key retriever to find the key. I just bought an SSD, did a clean install of the same OS on their, went to activate windows using the key found on the HDD and came back with this error code upon attempting to activate: 0xC004E003. I then ran the windows activation diagnostic MGAdiag on my HDD to see what was up. The key on there came back as 2- Oem SLP which to my understanding is a manufacturer OEM and can only work using the same mobo as when originally purchased. Since I highly doubt that this was a Dell/Lenovo or any other company type PC I'm really starting to believe that this is not a legitimate version of windows I'm dealing with. Is there any way for me to tell before I go out and spend $99 on a new key?