Can't boot windows xp installer from CD

Hi
I'm trying to reinstall windows xp on an old computer using an iso image I burned to a CD. I have inserted the CD and changed the boot sequence so that the CD boots first...nothing. I don't know what the next step is to solving this.

If it makes any difference, the reason I am installing in this way is because I couldn't uninstall windows first using control panel or command prompt in safe mode probably because I am missing the Undo folder and Backup.cab.

Hope someone can help me out.

Thanks

EDIT: Completely forgot to say. My computer is a Toshiba 1800 and I'm installing XP SP3 using a DVD

 

it must be a bootable iso image

 

It contains autorun.exe if I open it manually. Does that mean that it is bootable?
I made sure that I didn't just copy it to the DVD but actually burn an image instead.

 

did you use imgburn??

It will say "bootable" in the text given when you load the ISO into Imgburn,

http://s197.photobucket.com/user/indyank/media/techbliss/imgburn-2.jpg.html

above image shows imgburn gui with iso shown as bootable

if you load the iso image into image burn it will say if it is bootable,

did you use imgburn?? or nlite??

 

I used Burn for Mac because I only have the one windows computer that I trying to install the OS on, which doesn't have a working version of windows. I think I might just leave it because this seems to be above what I understand.Thanks for the help though.

 

okay, I do not know of any program that will burn a windows install cd on a mac,