user name and password woes

The dawg that originally set up postgres 8.0 on one of our Windows 2003
servers has left the company, and I have taken it over.
I need to use pg_dump on that server. When I try to, I get ‘user
"Administrator" does not exist.’
Next I try ‘createuser –U postgres –W administrator –P’. The response is
‘ERROR: user "administrator" already exists.’
I know PG requires a user with the same name as the Windows user and that
should be ‘administrator’ on this server.
Oddly I can connect to PG on this server through PGAdmin (through
postgres user?). Ultimately I want to create a database with a new name from
an existing database; I’ve done this from the command line on other servers.
Can’t, or don’t know how to, do it through PGAdmin.
I’ve also tried to delete and recreate the administrator user from PGAdmin
but I still can’t use pg_dump.
Tried all the passwords my colleagues can think of. I’ve searched the
forums and tried various things like setting pg_hba.conf to trust
temporarily and restarting.
Any suggestions greatly appreciated! Thanks in advance.

Charles Mortell
Advanced Planning Technologies, Inc.
Mississippi River port of La Crosse, WI
cmortell at apt-cafm dot com