How To Customize Xp Themes
You can a free tool called Resource Hacker to customize Windows XP themes.
Resource Hacker allows you to add new resources, modify existing resources or delete existing resources in any file. You can also modify EXE, DLL, CPL, etc files using Resource Hacker.
To customize a theme, you just need to open its .msstyles file in Resource Hacker and then you can replace existing BMP files with your own image files.
Once you finish replacing files, you can save the file and your new customized XP theme is ready to use.
You can read more about Resource Hacker at following link: