I'm satisfied with my Win10 upgrade (plus I have, and keep maintained, a clone of my Win7 system), and I would like to delete the Windows.old folder from my C: drive. However the delete process is not working. When I go to delete the folder, I have to provide Admin permission to continue the process, and I do so (I'm the single-user admin). A few moments later a window pops up saying I need SYSTEM permission to continue ... and I don't know what that is, so the process will go no further.
Any help in removing the large(25GB) windows.old folder from the C: drive is appreciated!