only have 3/4 of my screen

I am not sure what has happened here as this is a friends laptop, and i think her kids have done sum thing, on the right hand side of the screen its like you can only use 3/4 of your screen there is just a big black strip i have been into display settings and tried to change the resolution, that has not fix it, I have read the manual and cannot find anything, have tried using the hot keys to widen the window to full screen, have tried to do a system restore but no restore points will work. Hope i am explaning this well enough. any ideas would be great. thanks in advance. its an acer aspire 3620, laptop windows xp home.

 

Everything in the device manager is fine, the task bar is still at the bottom, the desktop icons and everything are normal, its just that, you no how with your cursor you can drag the side of a window to make it smaller, well thats what it looks like, like some one has drag the left side towards the middle of the screen, and its left a big black panel.:confused

 

Hi lynette00, Can you explain what you see a little more clearly. Is is just the open window that is partial, or is the taskbar also only partial? Is this happening on all open windows, or just your browser windows? If you could post a screen shot, that might be helpful.