How to install 10.4 on a partition on a Macbook Pro that was been upgraded to 10.6.8 10.4 was the original OS.  I have software that wouldn't run on 10.6.8 which I didn't realize until after I'd upgraded to 10.6.8.  I made a partition but restart/"option" won't recognize it.  How can I run the software that requires 10.4?

When I try to reboot, it's as if I'd never made the partition, even though it's on the desktop as a second hard drive. 



Why can't I access the partition as an option when I reboot?
You’ve made the partition, but it won’t be bootable until you install OS X on it. Boot from the install media CD holding C on boot, choosing the new partition as the destination for the install. Once OS X is installed on the partition, it will appear alongside your existing install in Startup Manager when holding alt/option on boot.