I tried installing Ubuntu Server 12.04 LTS, and it doesn't work. Well, it does, until the third step, in which it says it cannot mount the CD-ROM drive and tells me to insert the installation disk.
I am using a USB to install. If I put in the DVD into the drive and I try to boot it the computer just boots to Ubuntu (Ubuntu Desktop). I have a spare drive if this one is faulty, but I don't want to need to install it. I am also using the 64-bit version.