Server Error in Application "DEFAULT WEB SITE" "PHP" "Apache"

Question

i dont have any experience between PHP and Apach2 so 'Sorry'  I am configuring PHP with apache2 i have configured both 'INI' files but when i enter
http://localhost// it show me IIS7 page .
when i enter http://localhost/index.php then it show me error this
"HTTP Error 404.0 - Not Found
The resource you are looking for has been removed, had its name changed, or is temporarily unavailable."
and my index.php file located in htdocs folder.
help me in this matter.

i have already unistalled IIS service but still work