What OS CD are you using? You can not use a CD that is for another machine. If that 9.1 CD has a model number stamped on it, you can only use it for that model.
What exactly does the error message say? How much memory do you have installed? Did you run Disk First Aide first on the drive? Did you update drivers before trying to install? Updating drivers is important. This can be done from Drive Setup - just go to the menu and select update drivers, do not click on erase.