I just got a used MacBook Pro (early 2011, 17" i7) It came with a new install of 10.7 but no OS discs.
I have a retail DVD of 10.6.3 and I'm trying to downgrade the laptop to 10.6. (needs to match an office machine of mine)
The DVD will mount but the installer won't run. If I change my startup disk in system settings, on reboot, I get an apple logo on gray screen - nothing else. Same if I hold down C while booting the machine.
I don't have a FW800 to FW400 cable so I can't try a target mode install but I can get the cable if that will do it.