This is driving me bonkers. I accidentally slipped while trying a Shift-Ctrl-N (set Normal style) on the keyboard and the display has rotated 90 degress counter-clockwise.
Display and mouse. (When my hand slides the mouse to the right, it goes vertically up the screen, when I slide down it goes to the right; this does strange things to my brain at this hur of the night)
I'm typing this on the other machine, my old Big beige Box - same shared monitor - so this BBB machine with the CRT is OK, but the Laptop computer using this CRT is not OK.
The Laptop LCD is rotated too.
I must have triggered something in the laptop.
There is no Windows key and no (laptop) Fn key on this old beige keyboard. Whatever I did I did through this keyboard.
I've tried rebooting.
Run through (screen) right-click properties. I see nothing there that suggests rotation.
Run through troubleshooting. Nada.