I am a newbie here and I am trying to install Ubuntu 12.04.4 Desktop on my college machine which already has dual boot of Red Hat and Windows 7. I want to erase both the existing OS and install just Ubuntu. I am installing it from a DVD that I burnt from the iso image obtained from Ubuntu official site after the 700 MB download.
I am using an USB DVD drive and after pressing F12 I am selecting USB-CDROM for booting. But still the Red Hat version is starting and I can't install Ubuntu. I checked on the other laptop and the disk is burnt correctly as well as the drive is working fine. Don't know whats the problem.