I tried the SP3 update from MajorGeeks last evening.
It would get about 2/3 of the way through, then error out and uninstall itself. The error was a pop up box that didn’t give much information, except ‘access denied’.
I tried twice. The 2nd time, I shut down every thing I could. It errored out again, with the same ‘access denied’.
Not a promising sign...