I am having a hard time trying to install Ubuntu 12.04 LTS onto my desktop PC (Compaq Presario 061 with BIOS Phoenix Technologies, LTD 3.14, 1/17/2006), which currently runs Win 7.
I have backed up everything on the PC nto an external hard drive just in case things go wrong.

Here is what I have done so far:
1) On a macbook pro I used the "disk utility" program to mount the ubuntu iso image onto a blank DVD-RW.
2) I then inserted the burnt disk into the desktop and boot with CD-ROM drive as boot device priority #1. Doesn't work.
3) I tried again forcing the PC to strictly boot from the CD-ROM group, however no disk is recognized to be in the system...

After normal boot in Win 7, the DVD-RW is no longer even detected. The macbook pro will not even read the disk and requests immediate ejection.

Does this mean I lost access to a clean DVD-RW and will not be able to load ubuntu on my PC (maybe it's too old)? I am unsure if this is a hardware/software issue and have no way of checking to see if the disk itself is the problem because neither of my accessible systems will recognize the DVD.

SOS