StarSkin 

StarSkin allows you to change the view and appearence of your Windows XP box with the use of publicaly available themes.
themes desktop appearance skins windowxxp

Resource Tuner 

Replace the icon and other resources contained within 32 bit Windows executable files with other images, texts and sounds. Resource Tuner also makes it easy to translate any application, or fix and mark it as XP-enabled.
resource editor win32 dll exe icon viewer extract file dialog upx unpacker menu

XP Controls 

XP Controls is a powerful ActiveX DLL to give your common Visual Basic controls the look and feel of a Windows XP interface. Note: Window's XP is required.
activex xp controls vb visual basic dll common