The following bug has been logged on the website:
Bug reference: 7956
Logged by: Nav
Email address: navin.pro@gmail.com
PostgreSQL version: 9.2.3
Operating system: Windows
Description: =
I've posted the solution to my problem here:
http://dba.stackexchange.com/a/36901
It's because somehow, doskey isn't starting on my system (this problem was
happening even before I tried installing postgresql), but the point is that
it'd help if postgresql installation is made independent of something like
doskey. you'd probably be able to reproduce it by deleting doskey.exe from
your system and trying to install postgresql (any version)