Windows 8 pro activation key error?

[Skiddie]

I bought a new lenovo laptop and they installed windows 8.1 pro right then and there at the store, no clue as to where the activation kay could be written down or if it was at all. I have this watermark-like text saying I need to activate it yet when I go to do it, it says I can't. After opening some places a few times with some programs I found the key used, but I got an error message "This product key didn't work. Please check it and try again". I checked it, copy-pasted it, checked it again, tried a different one and I still couldn't get it to work. Even when I press the "Activate Windows Online" button it doesn't work. Error code: 0x8007007B

 

[popatim]

Take it back to the store where you bought it and have them fix there mistake.