Must not be a lot of IIS users around here anymore!
Nah...I still use it...I've just been a slacker in the forumn lately :-/
No matter what the text says about a procedure or module you still are not loading the dll. Either it really does not exist where you are telling php to look OR iis/php does not have the proper permission to run the dll. Check to make sure the internet user has permission.
You can also run the script from the command line as admin and see what happens. If it runs there then you know that it is an iis issue.
Sounds like the errors i get after installing a fresh wapm setup, have you included the path to the php.ini file to the PATH var (right click my computer, go to properties, advanced tab, then click environment variables, then under system variables you will find the path), altho i doubt thats the issue.
Check in the php ext folder for the extension its self if its not there download it, ensure your php.ini file is configured correctly for the extensions directory.
Other than that does IIS need the same or similar lines that apache's httpd.conf file requires to load php altho im guessing from the error that its loading the php module/extension just the ones that php wants to load (or some of them) arnt playing ball.