Lost Key

I just installed a 250G SSD in my Lenovo k450 1THDD, 12 Ram, i7. I restored it to factory which was Win 8 and installed Win 8.1 with a disk I

purchased online. To make a long story short, I just noticed my computer is not activated and does not recognize the Win 8.1 key, I was never

given a key with this computer and it is not located anywhere on the computer. Also tried to reset to factory again and it will not work, give

a message files are missing and to use the recovery disk to fix errors, when I use the Win 8.1 Recovery disk it gets to the installation and

when choosing what HDD drive to use , will not accept any.Can I somehow retrieve an original key?

 

I don't know if this will retrieve the original key, but here you go.
http://www.majorgeeks.com/files/details/mskeyviewer_plus.html