Modifying sytem files should be reserved for 
ADVANCED USERS ONLY!!!!!!!
ALWAYS BACK_UP YOUR DEFAULT, ORIGINAL SYSTEM FILES
BEFORE CUSTOMIZING THEM. ALWAYS CREATE A RESTORE POINT
BEFORE MODIFYING FILES AND FOLDERS!!!!

Inside the UIFile folder you will find two (2) folders.
One labeled "custom" and the other "default".
As it is obvious, the "custom" folder holds an altered version
than the original. The original UIfile is in the "default" folder.

The system files provided in the x64 and x86 folders contain the 
Explorerframe.dll with the custom UIfile already in place.

To return the systemfile back to the original, use a resource editor
like Resource Hacker, Resource Tuner or Restorator2007.

The custom UIFile is used for enabling custom images inside the explorer
window itself. And serves no other purpose.

The custom Explorerframe.dll files provided contain custom images to 
replace the navigation (back/forward) buttons as well as the UIFile.

It is strongly recommended to replace these files and images yourself
if you have the knowledge and tools to do so. Or to use the 

Windows Theme Installer
http://www.door2windows.com/windows-theme-installer-install-themes-in-windows-7-vista-with-ease/

Any and all modifications to your system are the responsibility of the user and
the user holds all liability.