IF you mean that whenever you switch it on, as soon as Windows appears, evrything (including the desktop, icons etc) is displaced to one side, then either your display is broken, or the positioning needs to be adjusted.
The position of the picture on the screen can (probably) be adjusted with the buttons on the bezel. They will probably allow you to make the picture taller/shorter, wider/narrower, move left/move right.
See if you can find instructions on
http://www.viewsonic.com/products/lcddisplays/
you will have to download them.
If not, try pressing the buttons. Try then one at a time and see what they do. Write it in a bit of paper.
Probably, if you pres one of the buttons (unless it is the on/off button) it will display one of those options, or possibly a menu that you can move up and down before selecting the one you want.
But if the button brings up something that isn't what you want, if you don't press anything for 30 seconds or so, it will probably turn off that option without changing anything.
Edited: bah, too slow