Overview:

I get the following message while installing PostgreSQL:

User 'postgres'could not be created: Access Denied.

Three solutions here

• This can be caused by UAC being ON in Windows 7 and Vista. 

-  Windows 7 UAC Help

-  Vista UAC Help

• You can run the attached .bat file to remove the PostgreSQL User name and reinstall PostgreSQL. .Bat File

• If you are installing PostgreSQL for a second time, you can just change the user postgres to "postgres1" and continue your installation too.