Manipulate Windows files

[ejdavis72]

I have been trying to go into my Windows files and change the dialpad background and a few other things and I am able to copy the file, move it to internal storage, then to my desktop of my computer and Gimp it but when I go to paste the image back into the Window files it says access denied. I don't know a way around this but I know someone here does and I would appreciate the help. Thanks