If you are using Windows XP, there is an image resizer "power toy" available as a download from Microsoft. See
THIS LINK http://www.microsoft.com/windowsxp/downloads/powertoys/xppowertoys.mspx
Once you have the
power resizer installed, you get a new option when you right click on a picture in your directory explorer. You can resize copies of one or more selected pictures, and store them in the current folder. There are several sizes pre-defined, and an advanced tab. With advanced options, you can define the new pixel size of your picture - and then it will fit anywhere that you have size restrictions.
Good luck trying it...