Assuming you already have Apache and PHP installed and configured correctly, what you'll need now are:
Downloadable at http://www.enterprisedb.com/products/pgdownload.do#windows
- And phpPgAdmin-4.2.2.zip
Downloadable at http://phppgadmin.sourceforge.net/
These were the latest versions at time of writing, but it shouldn't vary the setup that much.
Installation for Postgre should be pretty straight forward.
Choose a place to stash it, give it a root password and skip through the bits that don't really matter to you.
Extract phpPgAdmin and open up "conf\config.inc.php".
$conf['servers']['host'] = '';
$conf['servers']['host'] = 'localhost';
If you're unable to login (even though you're SURE the password is correct) and keep getting "Login disallowed for security reasons", see here.