I have IIS v5 running on a local machine and have recently loaded PHP
v5. Running phpinfo in my browser shows PHP is running OK.

I have now downloaded MySQL v5 and using the command line I can create
and populate databases.

The problem comes when I try to connect to the database from a PHP
script. All I get in the browser is a HTTP 500 server error with no
other error message in the browser. I've tried switching off my
firewall, checking PHP.ini and the connection string in my script but
everything appears OK.

I would be grateful for any suggestions as to where I'm going wrong
and what I need to do to get my connection working.