If you cannot download Display.exe , use (tiny, free, no install).
If this does nothing, your graphics driver does not support it. Proceed to Method 4 to force it.
if "%curr%"=="0" ( %DISPLAY% /rotate 90 ) else if "%curr%"=="90" ( %DISPLAY% /rotate 180 ) else if "%curr%"=="180" ( %DISPLAY% /rotate 270 ) else ( %DISPLAY% /rotate 0 )
This is the cleanest method because it does not require writing a script; it uses a built-in Windows command.