going back to root folder on clicking any link

Hi,
today i installed the drupal 6.19 on windows OS and the installation went smoothly.
Now i opened the index page and the url is http://localhost/drupal/index.php. On click on any link its taking back to the root folder and the url will be http://localhost/drupal/?q=admin and it displaying the contents of drupal folder .
Can anyone suggest me the solution.
I am using apache and mysql database.