I have a Microsoft Ergo keyboard and it has a F lock key. If that is off, the F keys don't work. I accidentally pressed it while holding alt since I wanted to take a screenshot of a window and hit that key instead of print screen. Now it's off, and I can't turn it back on, so I lost all functionality of F keys. I tried unplugging the keyboard and plugging it back in, no go. Is there a way to get it working again?