Windows XP Screen upside down

1. Go to Desktop.
2. Press Ctrl + Alt + up arrow key to make the screen from upside to normal state.
Or
1. Go to a blank spot on your desktop.
Right click
2. Go to "Properties"
3. Click on "settings"
4. Click on "Advanced"
5. Go to "graphics driver"
6. Click on "graphics properties"
7. Click on "rotation"
Reason: Within Windows, certain video drivers or graphics card chipsets supporting 180 degree screen rotation can cause the Windows display to be presented upside down. This can be (but is not always) tied to lowering the screen resolution in some accessibility programs.