To replace shellstyle.dll and other system files you will need to be owner of a file.
Taking ownership of files in Windows Vista:
Right-click the file you want to take ownership of , and go to properties.
Go to the Security tab.
Click on Advanced
Go to the Owner" tab and click edit.
Click on your name and apply.
Exit the properties to apply changes
Go once again into the properties of the file.
Go once again to the Security tab.
Click on your name and then edit, give yourself full permission on the file.
Apply and close. Done.
Now go to \\Windows\Resources\Themes\Aero\Shell\NormalColor\
Make a backup of shellstyle.dll (rename in shellstyle.bak)
Then copy the new shellstyle.dll
A shellstyle for vista
This kind of shellstyle looks like "Antique Red Shellstyle by *chefanim"
Because I like the pictures so much so I make the other colours for myself.
I hope someone like.
