Techy help required please

When I turn my pc on the screen display is rotated through 90 degrees anti clockwise.

However, if I unplug the screen from the pc, but leave the screen turned on and then plug the screen in once the pc has fully booted the display the right way up.

Any ideas on how to solve this, apart from standing the screen on its side?

Posted By: Claygate_Canary, Apr 7, 11:57:23