I would like to find out why the Ubuntu Linux 15.10 Live CD login appears sporadically after I disconnect and reconnect the COMCAST Internet carrier cable at the back of the Lenovo Think Station desktop PC after 15 minutes from selecting the Ubuntu LiveCD, Install Ubuntu Linux GUI item. If I do not   disconnect and reconnect the COMCAST Internet carrier cable at the back of the Lenovo, it apparently stays frozen with the Ubuntu logo and 5 red dots blinking on and off forever. We are installing Ubuntu 15.10 Live CD iso on a completely blank hard drive which was erased with the Linux command fdisk. At that time, I wiped out the Grub2 master record and MS-DOS table as well as the password table. Prior to that , I reconfigured GRUB2 so that I could install an open-source GUI package to delete hard diskpartitions.I would also like to know how to make the  Ubuntu Linux 15.10 Live CD login appear after 5 minutes consistently. This question may be important to people who buy computers with reformatted hard drives and wish to install Ubuntu Linux from a LiveCD. Any help is greatly appreciated. 
Ubuntu 15.10 Live CD login appears sporadically after I disconnect and reconnect the Internet carrier cable for the Lenovo Think Station
ubuntu;grub2;livecd