I have a MBA 2011 (i7) with 4GB of RAM. I run Windows 7 on Bootcamp and also run Parallels. I booted native into Windows 7 and noticed I only have 2.16GB useable RAM. I am running the 32 bit version of Windows, but still, this seems low. I am running a Dell 3007WFP 30" display connected to a dual-link DVI adapter. Not sure if that has something to do with it. Any ideas?