Getting set up in FSX Steam Edition- no mods yet- and I was resizing the GPS on my second monitor.  Apparently, I scaled it down a little too much, and now it's gone and disappeared.

 

I've tried turning it on and off (Shift-3, menus) and tried using window titles to see if it's still there but invisible (it's not).  Tried ending the flight and starting another, but the GPS is still missing.

 

So... how do I reset the GPS panel?

Sometimes when resizing gauges on second monitor the gauge within the window will dissapear, usually rightclicking within the window will get it back. Does it with stock FSX to.