The following bug has been logged on the website:
Bug reference: 13928
Logged by: Jeff Osborn
Email address: jeffrey(dot)osborn(at)am(dot)sony(dot)com
PostgreSQL version: 9.5.0
Operating system: Windows Server 2012 64-bit
Description:
When trying to run the initdb.bat file that resides with a path that has a
space in the folder name the install will fail. For example if the path is
C:\Program Files\Postgres that the initdb.bat file is run from it will fail.
This occurs on version 9.4.5-1 as well as v.9.5.0-1.