Hi, Laurie -
Welcome to Apple's Discussions.
You can not install OS 9 on that machine, for a number of reasons:
1. Install CDs for OS 9, those which came with a machine, are model-specific to the machine they came with; they usually can not work with any other model.
2. All Macs with Intel processors, which yours is one of, are incapable of using OS 9 as a boot OS under any circumstances. Since the installer on all stand-alone install disks for OS 9 (any version) will run only when the machine is booted to OS 9, this means the disc set can not be used with a machine such as yours.
3. Classic (OS 9 used as a program under OSX in order to provide an environment in which many OS 9 programs can be run) is not supported by Intel processor machines such as yours.
4. Classic is also not supported by OSX 10.5 (any version).
***
One possible work-around is to use an emulator such as
SheepShaver. Whether Sheepshaver will work sufficient for your purposes, or at all on your machine, is a different thing.
***
If you must be able to use OS 9, particularly as a boot OS, you will probably find it more convenient and cost-effective to acquire an older OS 9-bootable Mac and dedicate it for this purpose. Many pre-G5 iMac models, early G4 desktop models, or even a B&W G3 can be had for under US$200, some for as little as $50.
