Sorry for new topic - I was advised to do so.The story0. Win2000.
1. Installed SF2 1.2 from GOG.
2. It worked - I could play.
3. FreeSpaceOpenInstaller.jar used to install 3.6.10 and everything else it proposed.
I) Problem:
Most of basic files I had already downloaded but "Installer" didan't care to ask for and check if they are good - just kept downloading everything once again (several hours with breaks).I) Solution:
No a solution so far!
I) Suggestion:
Would it be difficult to add asking if user has a folder to check for the actual files before downloading them again?4. I've used Launcher55e.zip with proper settings from forum:
http://www.hard-light.net/forums/index.php/topic,65038.0.htmlII) Problem:
Choosing <Run> from Launcher gives error window:
strings.tbl is corrupted
File: cocalize.cpp
Line: 608
I pressed <OK> and get second error:
strings.tbl is corrupted
Line:6645
...
File: PARSELO.cpp
Line: 670
Every next one <ok> repeated second error until <cancel> .
I have no PARSELO.cpp, no localize.cpp neither any *.cpp file - at least in FS2Open installation folder.
II) Solution
German trace...
Browsing forum I have read about some similar problems but the closest ones ware with German version of SF2 installed instead of English one. The solution was an "German Fix Patch".
Yes! I had before another non English version
but not German. No a Fix-Patch for my language 
Following language trace ...
Then I read about changing language in the registry:
"How do I change the language settings for FS2 - The retail launcher won't let me?"
http://homepage.ntlworld.com/karajorma/FAQ/fs2-technical.html
Registry key:
HKEY_LOCAL_MACHINE -> Software -> Volition -> Freespace2/Language
had my language value instead of 'English' one!
5. Changing the value to 'English' - the version I've now from GOG - solved the Luncher <Run> problem.For any FS&FS2 maniacs benefit

Kind regards