I don't know why but I keep receiving this error code no matter what I do. It would appear the upgrade completes but when I login to the box I get "Installation failed" with the error code "DS_S_SUCCESS (0x0)". The whole thing doesn't make sense to me as success would be good right?
I have successfully installed SP1 into another Windows 2008 R2 box as well. So I don't understand why this one would fail.
Anyway, the error code pops up when I use the stand-alone installer for SP1 x64.