If you are running it as a module, it is more secure and you can make use of the .htaccess stuff.
Anyway, if the browser is just displaying the code, it sounds like its not running PHP properly.
You need to make sure that (if you are running it as a module) you have the following at the bottom of the LoadModule list (everything that follows, unless otherwise told, should be entered into your httpd.conf file):
LoadModule php4_module c:/php/php4apache.dll
(and of course make sure that the file php4apache.dll is in the c:\php directory)
Then add:
AddModule mod_php4.c
to the bottom of the AddModule list.
Next add the following two lines
AddType application/x-httpd-php .php
Action application/x-httpd-php "/php/php.exe"
above the bit that says:
#
This should be changed to whatever you set DocumentRoot to.
#
<Directory "C:/Program Files/Apache Group/Apache/htdocs">