Offering this for information...
While installing SP1, I selected the language option to install only languages on the DVD. I was assuming the "DVD" referred to the file I downloaded as the service pack. I got an error message about a missing common.resources.dll in the zh-hans (or zh-hant) folder.
I downloaded another copy of the service pack and ended up with the same result. The specified folder was empty, compared to similarly named folders with many files. I tried "spoofing" by copying files from another folder, but got a similar, but different, missing file message.
Next time through, I selected the option to install all language files, which led to an Internet download, and then things proceeded successfully to completion.
OK, I got through it, but I don't like the idea of installing a bunch of files for which I will have no use.
Bug in the download package?