Keyboard acts as if the Command key is depressed 100% of the time
Not sure if this fixes it but It's worth a try:

Open the on screen keyboard viewer and click on the cmd key:



When I have the cmd key pressed down it now becomes unpressed.

If you're not sure where you can find the on screen keyboard viewer it can either be here or you have to enable "Show Keyboard &amp; Character Vieuwers in menu bar" under your keyboard settings. And then click on show keyboard viewer in under the icon in the menu bar. Or just google how to show the on screen keyboard ;)