This page describes how to resolve the following error message: The specified module could not be found when installing PHP 5 on IIS.
After manually installing the ISAPI version of PHP 5 on Windows XP - IIS, you might see the error "The specified module could not be found" when you open any PHP page in your web browser.
This is not a bug in PHP. To resolve this error, check the .php application mapping in your IIS configuration. Go to Internet Information Services management, right-click "Web Sites", and select "Properties". Select "Configuration", and then the "Mappings" tab. Look for the ".php" Extension, and click "Edit". (If it is not there, you did not install the ISAPI setting according to the directions. See the links below.) In the executable text box, enter the path to the executable using the 8.3 naming convention. If you do not, IIS may treat everything after the first space as an argument, even if you use double quotes in the file name.
For example, the dll is commonly located at "C:\Program Files\PHP\php5isapi.dll". For that path, enter "C:\Progra~1\PHP\php5isapi.dll" (without quotes). Save and apply all the changes. Reload the php page in your browser and the error should be gone.