A few weeks ago I could rotate my display in XP. Just using the arrows with ctrl+alt would made the display shift 90 or 180 DEGREES. But it stopped working.
What happened? It was a convenient thing when I wanted to lay down and look at my PC.
Settings to rotate display by 90 degrees

Did Window update turn it off?

Any ideas?  Are you sure that the CTRL and ALT and Arrow keys are good.... such as trying a different keyboard? I am running Windows XP Home SP3 fully patched and when HOLDING CTRL + ALT down and selecting an arrow and releasing all 3 keys it changes the rotation, so not a MS Update for XPThanks. Just now checked on another computer. Same thing.  Running XP sp3 with latest updates. Has me baffled. Either an update or some freeware I put on both machines.
BTW, in Windows  7 it works as advertised. CTRL+Right arrow turns  90 degrees  to the Right.

Two or THREE weeks ago it was working perfect. 
Use the other CTRL button...That's a function of your video card, not Windows.  See if your video card mfr supplied a Hotkeys utility that would control that and see that it gets loaded at startup. Quote from: strollin on August 29, 2014, 09:42:34 AM

That's a function of your video card, not Windows.  See if your video card mfr supplied a Hotkeys utility that would control that and see that it gets loaded at startup.

Not the issue...it was working prior to now.

Windows Updates often include unnecessary driver updates for some reason, an update to the Graphics Driver could cause this.