Apple Mac OS X 10.4 "dvd keeps ejecting" Questions

...keeps ejecting the Mac OS X 10.4 Install DVD. If your computer ejects the Mac OS X 10.4 Installation DVD, it means that there's a good chance that your Mac doesn't have an Apple internal DVD drive or ...

...to solve some of the problems. I put in the disk and it tells me it will not start up from the dvd, please check to be sure the disk is in the drive. I'm running an old external dvd drive.

mac 0sx 10.5.8 estion: "i ran disk utility and everything was cool went then I click re start and the computer won't restart and the pilot light keeps blinking... I cab eject the mac disk still ...