psql language

Hello,

I just installed pg-8.4 on Windows XP but ran into
some unexpected problems.

I am working on some tools to aid English-speaking
learners of Japanese. This of course requires me
to regularly display and enter Japanese text on my
machine, so I have the Regional setting, "Language
for non-unicode programs" set to Japanese although
the locale language is English. This allows me to
to work with both english and japanese text in the
windows console (cmd.exe) just fine. Psql also
worked fine until 8.4.

With 8.4 though, psql presents messages in Japanese.
Since I am still a beginner at Japanese myself, this
is a problem.

FWIW, I tried doing "SET LANGUAGE en_US" and
with every other locale-related variable "LC_ALL",
"LANG", "LC_MESSAGES", etc, I could think of,
before running psql but with no effect.

How can I tell psql (and any other command line
tools) to use english messages?