PT 10 / PT 11 / PT 12 Co-Install On WIN x64?

Hi there,
Last year i received a PT 11 installation when i purchased the Eleven Rack. It included the PT 11 + PT 10 licenses. I have them BOTH installed on my WIN x64 PC,

I just subscribed for the PT 12 monthly. and i received the download links on my Account.

I have PT 10 + PT 11 installed right now on my PC. Can i go ahead and install PT 12 on the same drive as the others? or should i uninstall the older versions?? Can i install PT 12 on a new drive partition?? i want to continue using PT 11 and/or PT 10 for few old RTAS plugins....Please help.

PC: WIN 7 Ultimate (64bit) with i7-3930k 6core, 16gb Ram., 2 internal
HDD

THanks Much,
Sanjay.