Changing shell32.dll, authui.dll, imageres.dll?

Hello. Recently I downloaded a Vista msstyle. VD-Glass UNLEASHED by ~TQDgamer98 on deviantART. It had the msstyle, plus the other stuff (the dlls you need to change). I got everything modded (but 3 dlls) and such, and i suggest this theme to everyone. But for some reason, everytime i go to the system32 or whatever folder, and change the authui.dll to authui.bak.dll, it allows me. UAC flashes up, i give it permission, then suddenly when i try to copy the modded authui.dll, it asks the first bit of permission (not the UAC one) then my screen darkens, like right before UAC comes. Then...

It flashes back. I check the folder, and the dll i just copied isnt there. I try again, UAC doesnt let me say continue, then it doesn't copy. Now heres the bad part: the authui.bak.dll doesnt let me rename it.
Does the same thing, UAC just comes and goes with out me clicking continue.

Not to worry, i just do system restore to about 5 minutes earlier. But still, this is a sick theme. I want to have its bonuses.

I am running Vista Home Premium 32-bit. I have LogonVista installed (Could that be why imageres.dll doesnt work? Well what about the others. I dont think they all fail because of LogonVista.)

Thank you for taking your time to read this. All suggestions are appreciated.