BUG #1873: "Invalid username specified" during install

Hi,

Warning: I'm a total noob.
See below for the original bug report.

I was able to reproduce this problem on postgres 8.1.5 and I think I
have a fix.  Here's how I reproduced it:

1. Install postgres as a windows service (create the default posgres
WinXP account, etc)
2. Uninstall postgres.
3. Attempt to install postgres again

Result:
The installer cannot create the default postgres WinXP account.
Error message: "Invalid username specified: Logon failure: unknown
username or bad password."
However, if you change to any other account name then the installer will
finish as normal.

Fix:
The problem is that uninstalling postgres does *not* delete the postgres
WinXP account that was created during installation.  You have to
manually delete that account yourself before postgres installation can
successfully recreate that account.

Here's some advice that might save you some time:
It is *not* sufficient to merely delete the user *profile* via control
panel -> system -> advanced -> "settings" button under "user profiles".
  You *must* delete the *whole account* via control panel ->
administrative tools -> computer management -> navigate to "users" via
(System tools ->  local users and groups) and delete the account that way.

I hope that helps.

Gus

====================
original bug report found at
http://archives.postgresql.org/pgsql-bugs/2005-09/msg00061.php
====================

The following bug has been logged online:

Bug reference:      1873
Logged by:          Lee Benson
Email address:      lee ( dot ) benson ( at ) issinc ( dot ) com
PostgreSQL version: 8.0.3
Operating system:   Windows XP Pressional
Description:        "Invalid username specified" during install
Details:

I am trying to reinstall Postgres 8.0.3 after developing a problem using
psql (command line) where I was getting the "password authentication
failure" message.  When I tried to reinstall, I got the "Invalid username
specified: Logon failure: unknown user name or bad password" error.  If I
change the default user from "postgres" to something else, the installer
will move on and finish, but I still can't use psql at the command line.
What am I missing?