So this is an update to my post on Fixing Wamp not so friendly extension.
I was trying to configure WAMP in WIndows7 so I can play with postgres 8.4. So I put on the extension php_pgsql and php_pdo_pgsql and it doest work.
To fix this you must find the libpq.dll file in C:\wamp\bin\php\php5.X.X whatever your version is) and put it on C:\Windows\System32 AND to c:/wamp/bin/apache/apachex.x/bin (this is the difference with my post) .
Please note that just in case you must install a WAMP of the same bitage that your postgres version. In my case Wamp 64 bits didnt work on my Postgres of 32 bits, so i reinstalled and used the Wamp of 32bit.
Hope it help anyone!