UxTheme Patcher for Windows Vista description
A patched uxtheme.dll gave you the freedom to use un-signed custom visual style

Are you tired of Vista's Aero theme?

A patched uxtheme.dll gave you the freedom to use un-signed custom visual style in Windows XP but in Windows Vista you have to replace three dll files to use third party visual styles.

Those three files are uxtheme.dll, shsvcs.dll and themeui.dll

How To Install
1. Login as a user with Administrative privileges -or- have Administrative
credentials ready (check under the keyboard for a slip of paper).
2. Navigate to %systemroot%System32
3. Right-click uxtheme.dll and click properties.
4. Take ownership of the file and close dialogs.
5. Repeat steps 3 and 4 for themeui.dll and shsvcs.dll
6. Right-click uxtheme.dll and click properties.
7. Give yourself (or group) Full Control permissions and close dialogs.
8. Repeat steps 6 and 7 for themeui.dll and shsvcs.dll.
9. Rename uxtheme.dll to uxtheme.old.
10. Rename themeui.dll to themeui.old.
11. Rename shsvcs.dll to shsvcs.old.
12. Copy patched files into %systemroot%System32
13. Reboot (yes, this is really required)
14. Enjoy!