BUG #4826: Cannot install Postgresql

The following bug has been logged online:

Bug reference:      4826
Logged by:          Tobias Storm
Email address:      tobias_storm@ofir.dk
PostgreSQL version: postgresql-8.3
Operating system:   Windows XP Home Edition
Description:        Cannot install Postgresql
Details:

When I am trying to install PostgreSQL I get an error message which say:
(Due to this I am not able to install PostgreSQL)

Failed to run initdb: 1!
Please see the logfile in: C/Programmer/.......

When I go to the logfile it says:

The files belonging to this database system will be owned by user SYSTEM.
This user must also own the server process.

The database cluster will be initialized with locale Danish_Denmark.1252.
The default text search configuration will be set to danish.

creating directory CProgrammerPostgreSQL8.3data ... initdb could not create
directory CProgrammerPostgreSQL File exists


Can you tell me how I can solve this problem?