I have four hard drives on my Mac Pro. The drives contain the following: Drive 1: Leopard 10.5.2 Drive 2: Blank - formatted for Mac OS Extended (Journaled) Drive 3: Leopard 10.5.2 and Windows XP Drive 4: Used for Time Machine backup How can I install Tiger on Drive 2? If I start to install Tiger in the Leopard drives it tells me that it is not possible. Pressing C with the Tiger DVD inserted doesn't help. Thank you.