I have an old iMac that won't boot up anymore. I have the OS X install disks but I can't get it to boot from these disks. No need to save anything. Any suggestions?

I have an old iMac. Not sure of the operating system but the install disks say OS X. The computer will not boot anymore and all I keep getting is to restart and when I do I keep getting the same message. I do have the install disks but I can't get the computer to install, or for that matter, read the disks. I would like to rebuild the computer from these disks so that I can continue to use this computer. There is no need to save anything on the computer as I backed it up months ago. Any suggestions as to how I can save this computer and not have to recycle it?