BUG #4133: Installation error

The following bug has been logged online:

Bug reference:      4133
Logged by:          Anthony
Email address:      Anthony-s@ya.ru
PostgreSQL version: 8.3.1
Operating system:   Windows Vista Home Premium
Description:        Installation error
Details:

I have a problem with installation.
1. If I unchecked "To initialize claster databases" during installation then
intallation will be complated succesful. In this case doesnt work follow
comand:

C:\Program Files\PostgreSQL\8.3\bin>initdb -D "C:\Program
Files\PostgreSQL\8.3\Data"

C:\Program Files\PostgreSQL\8.3\bin>initdb -D "C:\Program
Files\PostgreSQL\8.3\Data"
The program "postgres" is needed by initdb but was not found in the same
directory as "C:\Program Files\PostgreSQL\8.3\bin/initdb".

Check your installation.

2. If I cheked "To initialize claster databases" during installation then I
have got error and installation roll back.

Failed to run initdb: 1!
Please see the logfile in C:\....\tmp\initdb.log.

I unchecked "UAC"and open access for posgres folder but nothing change.

Im looking forward to get help from you.