Linux will not boot

I have downloaded ubuntu-10.04-linuxcnc3-i386 (3).iso onto both a Flash drive and a CD-R with the understanding that I should be able to boot my Windows PC with Linux by using F12 and then booting directly from either the drive or the disc. However, when I try this, I only get a black screen with a flashing cursor.

What am I missing?

Thanks,

Brian

Put the CD into a working computer and try to look at the files there. if you see one 600+ MB file called ubuntu-xxxx.iso, you
have created the CD wrong. You need to burn the iso file to the CD with a CD burning program that can create
the iso file system on the CD, not record it as a data file. When burned to the CD as an ISO, it will then
be bootable. When you do this, there will be a tree of directories on the CD.

Check your CD burning program for a "burn as ISO" option. Some CD burning programs do not
have this option, or hide it very well.

Jon