postgresql as windows 2000 service problem

The path for the postmaster user is correct
If I run: runas /noprofile /user:.\postgres cmd
and from then cmd windows if I type PATH I get the correct path
with postrges\bin and postgres\lib appended. If I run pg_ctl from
this window I get administrative rights error (as expected because of the
/noprofile parameter)

If I run (as admin) runas /user:.\postgres cmd
and then pg_ctl start I can start the postmaster (or: runas /user:.\postgres "pg_ctl start").

So I believe it is not an wrong installation of postgres.
It is a service error to postmaster, or a windows 2000 bug.

Did anybody succeded in running postgresql service under windows 2000?
I have done it in windows XP and I have read that it is running under
windows NT.

Thanks John