The following bug has been logged on the website:
Bug reference: 15769
Logged by: Nick Anderson
Email address: nicholas.anderson@zurichna.com
PostgreSQL version: 9.6.5
Operating system: Windows Server 2012 R2
Description:
When trying to install PostgreSQL 9.6.5 on Windows Server 2012 R2 an error
displays that says "Problem running post-install step. Installation may not
complete correctly. The database cluster initialization failed."