base path issue

After enabled the subdomain module(not according to the README file), my base path of all the links in my drupal site change from "http://localhost/drupal" to "http://localhost". I want unintall or disabled it.

However, whenever I try to go to "http://localhost/drupal/admin/modules/", it will redirect to "http://localhost/admin/build/modules/list/confirm" which is missing my installation path. So I can't do anything about it now.
I am now looking for a way to fall back the situation that it was.
Can anyone guide me how i can fix this? Thanks!