I have an early model 17" Mac Book Pro, and when I purchased the LR4 upgrade I got a message that it can't be installed on this computer. I'm guessing the reason is that it doesn't have 64 bit capability, but I don't know how to check -- I couldn't find that info on the "About this Mac" lists. LR4 installed just fine on my newer desktop Mac Pro and also on my wife's later model Mac Book Pro.
Questions: How do I find out what bit version is on a Mac? Is there anything I can do short of replacing a laptop which otherwise works well? I'm using LR4 much more than I did earlier versions, but coordinating LR3 on my travel laptop and LR4 on my main computer is a non-starter.
I'm still running 10.6.8 because I have several PS plug-ins, printers, and scanners, and I've been too busy to research upgrading everything. I expect to install CS6 on the Mac Pro as soon as it is released, but I assume the laptop will react with the same problem.
Am I right that this is a 32 bit issue? Will CS6/LR4/Mountain Lion require new hardware? Would appreciate any guidance on the next step.