Can I maximize windows on a second monitor? I recently added a second monitor. I want to be able to keep a window maximized on this screen. Clicking the maximize button when in this monitor causes the alert sound to play and the window does not maximize. 

How can I maximize a window on the secondary display?
For some reason I am now able to maximize windows on my second display.

The only change I made was to try it with Finder per @drivec's comment about stock apps vs. other apps. 

The direct answer to my question is: Yes you can maximize windows on a second display. 

I have no idea why it did not work earlier.