Trouble Booting Live CD

[Lanserr]

I have a copy of the ubuntu 8.10 live cd and I'm trying to install it along side Windows 7. The problem is that my computer refuses to boot from the cd when I change the boot order in my system config and using the cd to install a second boot option in grub doesn't seem to be working. I tried the reboot with help option and it continues to load windows 7 on the restart without giving me the option to boot from the cd.
Any ideas?

[wpshooter]

Are you sure that you have a bootable/burned ISO image of Ubuntu on the CD ?

[Lanserr]

I used the cd before and fully installed ubuntu but then I later upgraded to windows 7 from XP and full whiped my hard drive.

[Lanserr]

Okay I figured out the problem. The live cd keeps installing the boot help to my drive C, but my drive C is simply an external hard drive. The live cd doesn't give you an option of where to install the boot assist. I know I could rename the drives, but wouldn't that break all the paths in my computer?