I re-formatted a spare harddisc, installed windows xp, and then added mach3. Same problem with glitches. I'm now open to try anything, so . . .

I downloaded ubuntu-8.04-desktop-emc2-aj13-i386.iso onto another machine, then burnt it onto a disc. However, when I put this disc into the cnc PC with the reformatted harddisc (setting it to boot to CD in BIOS) I get 'Boot from CD :' then 'disc boot failure, insert system disc and press enter'. It does not recognise this as a boot disc. Not being familiar with linux install I don't know how to proceed from here. Any offers?