in x15r1, The right windows key has the lock. So Fn+RightWin. Worth a try.
I was typing and saw a notification popup with a message that said "Windows Key Disabled". Now my Windows key does not work. I checked online, but videos and tutorials say with press Fn-F6, but that does not work on the x17 R2. The F6 key is marked with a letter E, and doesn't seem to be assigned to anything (and does not do anything with pressed with the Fn key). Any ideas how to fix this?  
x17 R2, Windows key disabled