Nobody is above mistake. You may find your screen rotated after you have erroneously press some series of keys, do not get mad at yourself. There is solution to it. Re-setting your screen back can be done in two ways.

Here is the solution when problem like this occur. Here we go!
See more: http://computerwidgets..com/2012/12/how-to-rotate-screen-in-windows-xp.html

Hello Members,

You may have accidentally hit a sequence of keys and now you notice your Windows XP screen is upside down. Don’t panic: It’s easy to use a couple of quick hotkeys to rotate your screen back to normal. Or, maybe you would like to flip your monitor to sit vertically instead of horizontally. To do so, you will need to rotate the screen to accommodate your monitor’s orientation.

1. Press "Ctrl-Alt" and an arrow key (left, right, up or down) to rotate the screen.
2. Continue pressing the hotkeys and arrow keys until you reach the desired rotation. This works with most video drivers on Windows XP. If it doesn't, proceed to Step 3.
3. Click “Start,” then “Control Panel,” then “Display,” then the “Settings” tab. Click the “Advanced” button. Check for an “Orientation” option. Select your desired orientation.

Best Regards,
Tony Mccallum

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