Warning1: Server software ................Unknown web server
Warning2: URL rewriting support......You need mod_rewrite to use friendly URLs with SilverStripe, but it is not enabled.
Warning 1: may be, but the yours will work
Warning 2: is essential, but not the problem
Use this forums search function, it's pretty full of links 'bout mod_rerwirte.
When your apache2/linux skills are not good sometimes it's helpfull to make a new installation, setting the .htaccess-file to chmod 777 before. But mosty it's a stupid little mistake in .htacess or apaches mod_rewrite-modul is not loaded on your server.