@shaffer
"With the upgraded W2K (case 2) even the CD only installation has been working."
Sounds to me, that if set up correctly (Hardware, drivers & OS knowing each other) your sytem is capable to run GalCivMultiMedia.
"upgraded GalCiv to 1.10A.073 [...] New games abort whenever a (new) expansion pack anomaly are being explored or surveyed."
A wrong path in an .ini file?
Would be interesting to know what happened, if you FIRST) upgraded Win2000, 2) Installed German version 3) upgraded GalCiv to 1.10A.073
[stuff not relevant to GalCiv]:)
"needed the CD whenever I wanted to play"
I was a VERY patient DJ all the years, until some weeks ago my CD-drive died & disabled in this process my Cleopatra-CD (with my new SurfingII-scenario in its final development stage). Well, was I PISSED. Thank you, Sierra, thank you, impressiongames, thank you, breakawaygames. I looked for NOCD versions, but gave up as on gamecopyworld.com there was no german up to date cleoV2.1 version and those myriads of (russian etc.) sites tried to install dialers & other nice programs prior to let me download something. Well, was I PISSED. I have not the time to look myself for this one JNE statement which is to turn into JMP. Thank you, Sierra ...
Probably I buy another Cleopatra-CD @ ebay to finalize my scenario for the Heavengames community.
[stuff not relevant to GalCiv];)
"I have not been able to uninstall only the base game and keeping multimedia."
Sorry, I was not clear enough. Without knowing the patching-routines, I would never suggest to try such things (and even with knowing: Murphys law

).
What I would like to do:
1. install the game from the 'german' CD
2. upgrade/update with the expansion pack
3. replace the 'german' pendants of the 'english' text files, which aren't changed & therefore already replaced by the patch, with 'english' files from a base game downloaded via SDC. This should work with simply copy.
If this doesn't work I'll
1. install the 'english' base game downloaded via SDC - and burn my CD with its multimedia glitz :(:(:(
OR
2. wait for something new
"possible solution could be to make Stardock Central (SDC) aware of language specific files"
They will LOVE this idea.

Hipp, hipp, hurray, if they do it!!!
Ok, but what about the patches containing ALL the (I asume small) language-specific files? Sooner or later they will be ALL changed (and included) anyway - and it will patch ALL international versions.
--
@Darklor
"then I installed the game two times."
From the CD or the downloaded?
"used another path"
Maybe the first and only installation works if ANOTHER path is used (conflicting definitions of a default path)
"the Problem could be the german save files."
Please clarify, are the NO saved games in the two installations prior the patch?