Trouble installing M 44

[jonnymacbrown]

I am in Win 7
If I follow the instructions and install into Programs/HPS/Minsk I can't update.
If I install into a folder I create; M44 I am able to open the game and update but then I often can't read battle files sent PBEM
I cannot download 0623_01c: The Destruction of Army Group Center - no Fixed Units_Alt rebalanced by Michael Smith and play by email although I can read it for a head to head game
I cannot download 0623_02: The Battle for Byelorussia - [HTH]_Alt successfully at all although the map files work.

Every time I try to install I get first this message: String ISDX_ERR_INTERNAL was not found in string table I click OK
then this message: Error ISDX_ERR_INTERNAL
I click Ok, can read the game but not without the above problems

I have never had this problem with any other game.
Please help jonny