Other computers connect to the web server but cannot read the web page

Need Help...

Running Apache 2.2 and PHP 5.2

Installed Apache and PHP without any problems on WINDOWS Server 2003.
Windows Firewall is OFF.

I can access my web pages (both .php and .html) on the machine with no problems
using 127.0.0.1 and the lan-ip address 123.23.23.123, port is 80.

When trying to access it from other computers in the lan, the
browser connects to the apacher server (123.23.23.123)
BUT does not load the page.

Using Firefox in Windows, it want to open the file index.php (like a document)
instead of loading it. I tried downloading the file and opening it. The
file was empty.
Using Safari in Mac, it wants to open an octet stream.
Using Firefox in Mac, it wants to open an Untyped Binary Data file.
Using Internet Explorer, it loads an empty page.

If this is a firewall issue, I should encounter something like "page cannot open".

I can access the web page, it just does not display.