Change Aspect Ratio in WinXP?

I have a plasma widescreen and I hooked up my laptop to it using a vga cable. The picture is awesome, except, it's 1028x768 in 16:9 aspect ratio. Which means, the pictures are too wide. Is there a way to change the aspect ratio or anything in Windows XP so I can watch images from my laptop with the correct aspect ratio? Thanks.

Changing the picture aspect ratio has got nothing to do with WinXP. It is to be done in the software player you are using to play the video or in the decoder you are using. What are you using anyway? I would recommend BSPlayer + ffdshow.

You'll have to set the desktop resolution to a 16:9 output, i. e. 1088 x 612 or 1280 x 720. 1024 x 768 is 4:3, which I assume is being stretched to fill the 16:9. Right-click the desktop (not on an icon) and select Properties, click the Settings tab and adjust the slider and Apply. If no picture shows, do not press anything, it will revert after 15 seconds. If for some reason the computer or display is incompatible with the setting you may get a scrambled picture or none at all, but typically unsupported settings aren't selectable.