git-gui appears to not respect Windows 7 settings on Display Language.

For some unknown sorcery Microsoft does not refer to 'Locale' the same
as UNIX. There is only a display-characters method, only if a
character set is not unicode. For actual display of language they have
now on 7 a package downloading mechanism to have the whole system show
a language.

On 7 right now I have locale on Greek so that any non-unicode programs
will work with that. But the display language is English and no Greek
or other non-English package has been installed. The location is also
Greece but that doesn't affect other programs either.

In general these settings make almost all programs to display English
by default. Only a minority like git-gui don't.