I dont know how dunfiddlin replaces his modded shell32.dll files . Yes, I do agree that it is possible to edit dll files . I also edit those sometimes . But I have never edited shell32.dll. I edit imageres.dll off and on to change system icons . I can share my procedure in this regard, if it is needed, or if it is helpful .

First of all, it is to have a system image backup, if there might be a further trouble. Then edit the dll file, and save the result on desktop, with the original filename. Then go to the actual location, and rename the actual one as filename.old (as you have taken ownership, you are permitted to do it). Now pot the modded one in the actual location, and restart, either computer or explorer. If it is to change anything, the change will take effect.

I am saying that it is the procedure that I follow, and cannot claim that it is the only procedure, coz perhaps in devart there is a tiny program called windows 7 system files replacer, made by Kishan Bajaria.