Unable to install Netbackup 7.5 media server

Hi,

    I want to install in a Linux (Centos 6.4) Netbackup Media Server with an image from my SymAccount Connect (I've checked the md5). During the installation I'm not been asking for "Do you want to install Master or Media Server" and the installation is proceeding with Master Server installation. Do I'm missing something?

Master Server : Windows 2008 R2 Netbackup 7.5.0.7

Thanks,