Am trying to install ubuntu 12.04 on a pentium 4 with a hard disk that's been totally wiped clean. Have made an iso image, burned it on a cd and it has been verified. Checked to see if separate files have been burned on cd and they have. When I boot to the disk I get the word unbuntu with some progress dots, 5 min later it goes to a red screen with the mouse arrow on screen. It has stayed in this condition for over half an hour now. Help?