The feature to add your own visual styles to Windows XP is locked by default and you need to replace the original uxtheme.dll with a patched unlocked one to be able to add visual styles to the operating system. Download the patched uxtheme.dll from Softpedia and do the following. Rename the original file which can be found in the system32 folder of your Windows XP installation to uxtheme.dll.old and move the downloaded version into system32. You will have to restart your computer afterwards before the changes are recognized.