Windows 8.1 oem and reinstallation

May 7, 2015
I guys!

I've just received my new x51 r2. It comes with windows 8.1 oem. I want to reinstall windows 8.1 on a SSD but I didn't receive a windows installation disk. I tried the Microsoft tool to download it and make a thumbdrive, but they ask me a product key right at the beginning... Thing key is oem...I can't enter it in the dialog box. Do you guys know a workaround?