Installation problems!!!

I'm trying to install Elgg on a website. It is on the site's root directory. So far I'm on the installing.php (http://www.domain.com/install.php) and stuck up as I'm having problems. Whenever I hit the 'save' button an error page appears. It says:

Not Found

The requested URL /action/systemsettings/install was not found on this server.

 

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.


Apache/1.3.41 Server at -------.com Port 80

Help please! I have tried the trouble shooting methods from the installation documents but nothing seem to work.

Thanks in advance!