I have installed Moodle 2.4 server on machine with window 7 by downloading the package available in moodle.org which includes XAMPP server .It is installed properly and is accessible from all client machines with windows operating system. The problem is that when we try to access the server from machines having Ubuntu it is not accessible. Pl help what to do.
You should not use that XAMPP package to install Moodle on a production server. That package is only suitable for "localhost" test installations of Moodle.
Windows 7 is also not suitable as a server operating system.
Also, check that you've got the correct '$CFG->wwwroot' value in your Moodle config.php file. "localhost" won't work.
Please explain what happens when a Ubuntu user tries to access that Moodle site. What happens? Do they get an error message?