Drupal 4.7.2
Linux
PHP 4.3.8
MySql 4.0.18
Apache 1.3.29

When I attempt to access my drupal site http://www.myserver.com/drupal-4.7.2/index.php

I get the following error:
"The server encountered an internal error or misconfiguration and was unable to complete your request. Your administrator may not have enabled CGI access for this directory."

I have not had to enable cgi access for any directory in which I have a PHP program installed.

The file permissions are the defaults from the installation.
My httpd.conf file doesn't seem to be involved.
There's a drupal-4.7.2/.htaccess file which is unchanged from the installation.

Is this a legitimate CGI access error?
If so, which files and which directives need tweaking?
If not, what should I test to track down the real problem?

Thanks in advance for your assisitance.