Other Directory

Hello, I am a WordPress Newbie,
to test the system I installed a wordpress system into a subdirectory on my server. For example I have the url http://www.abc.de I installed my wordpress system in http://www.abc.de/fgh.
I tried out wordpress and created a webseite. Now I registered a second url http://www.fgh.de on my webpackage and changed the dns setting.
I can reach my site by http://www.fgh.de but when I click in the menu I get the old adress with the subdirectory, e.g. http://www.abc.de/fgh/?page_id=11

How can I change that? How can I change that die links also point to http://www.fgh.de/?page_id=11 (example)?