Thanks for your answer,You'll need to partition your drive or use an external drive and with two drives you can have two operating systems
Disk Utility. And yes, reboot from the Leopard DVD, select the new partition, install, et voila.Thanks for your answer,
i have to make the new partion with diskutility or bootcamp?? , after how to install leopard ?,i put the leopard dvd and restart mac and after which key of keyborde i have to hold that i can choice that partion i made ??