PHP 5 mysqli help

Hi, I need help with php 5 and Mysql 5. Im brand new to php and an mysql but I like to jump right into things so here I am. I know php5 doesn't come pre-compiled with mysql but you can load it dynamically as an extension but then when i do that and it says that it loaded the extension then i try to use phpmyadmin and it say cannot load mysqli extension tried but failed then a link to doc's. I have mysql installed correctly and php is loading fine into iis 5 so i dont know whats wrong. Ive done searchs on the php site to find out how to load mysqli nd it says you have to comile it or something so do i need to do this cause idk how. Any help would be greatly appreciated even if its just a hey im in the same situation thing or Ive been there or a small nudge in the right direction. Thanks Colin.