How can we rotate desktop of the computer screen?

How can we rotate desktop of the computer screen?

This has nothing to do with your monitor settings as suggested above, it is a windows setting!!!

Right Click on a blank piece of your desktop, in that menu select "Graphics Options" > "Graphics Properties.

That will open a Pop-up Menu, you'll need the 5th tab which says "Rotation" and select the option you want from there.

You can alos try holding down <CTRL> + <ALT> + Any cursor key and that will rotate your desktop too (Up = Upside down, Down = Normal, Right = 90 deg clockwise and Left = 90 deg anti-clockwise)

Hope this helps