Here is a repost of a post I did last year,
Here is a free tool from Microsoft for Windows XP it is called image resizer … install it and then browse to the pic you want to resize, right click and chose resize image. Choose the size and it will create a new smaller image in the folder. Very simple.
You can download it from here. Hope this helps.
http://download.microsoft.com/download/whistler/Install/2/WXP/EN-US/ImageResizerPowertoySetup.exe