I guess that depends of the driver/GPU/settings used, but I knew that you could rotate screen with "key" + arrows. At work had to "fix" some of these PC's, 'cause the user had accidentally pressed "something".
Weird, tried with laptop and checked the settings; rotation is enabled and hotkeys are Ctrl+Alt+Up/Down/Left/Right. Though I've NVIDIA GPU and Intel GPU in this, but I did select Intel for use. At work those were Intel's GPU (on laptops), which had this rotation option.
Doesn't work on mine. And I have Intel based onboard graphics. Right now, I am switched to the ATI graphics. My card supports rotation, but I tried an assorted combination of the keys you guys listed above, & no screen rotation.
However, I can manually do so by using the mouse to right click on the desktop, then personalize or whatever.
If your screen rotates via hotkeys, it was more than likely set up to do so via either your HP/Compaq/IBM etc manufacturer in their onscreen keyboard settings they came preset with, or some OEM distributing their special Windows branded computers, with assorted hotkeys enabled.
I do not think that most computers have this by default on a basic, clean installation of Windows. It may also change from region to region. Mine is USA.
On my husbands laptop if he has for example Microsoft Security Essentials open on the screen then holds down altgr key and presses an arrow key it will auto scroll the tab tops of MSE. In other words it will move from the updates tab to the scanner tab etc.
"ALT GR keys -The ALT GR key is on the right side of the keyboard on some non-U.S. keyboard layouts. ALT GR is equivalent to the CTRL+ALT key combination"