This screen gives you the list of already recognized repositories. You can add other sources for packages, like an optical disc or a remote source. The source selection determines which packages will be available for selection during the next steps. For a network source, there are two steps to follow: Choosing and activation of the network, if not already up. Selecting a mirror or specifying a URL (very first entry). By selecting a mirror, you have access to the selection of all repositories managed by Mageia, like the Nonfree , the Tainted repositories and the Updates. With the URL, you can designate a specific repository or your own NFS installation. If you are updating a 64 bit installation which may contain some 32 bit packages, it is advised to use this screen to add an online mirror by ticking one of the Network protocols here. The 64 bit DVD iso only contains 64 bit and noarch packages, it will not be able to update the 32 bit packages. However, after adding an online mirror, installer will find the needed 32 bit packages there.