The HP Support Assistant does not interfere with the screen rotation. The problem is with your display adapter. Since most of the HP use Intel HD graphics cards, you can use the following combination to rotate the screen:
- 0 degrees (normal/upright): Ctrl + Alt + Up Arrow
- 90 degrees (quarter turn clockwise): Ctrl + Alt + Right Arrow
- 180 degrees (upside down): Ctrl + Alt + Down Arrow
- 270 degrees (quarter turn counter-clockwise): Ctrl + Alt + Left Arrow