I am running Windows 7, I just installed Cygwin for the first time today so I have been playing around with it. I am now wanting to start using Git as well.
From wha
If by some unlucky twist of fate, you're dealing with a git repository where some commits in its history are say, a few gigs in size, then you will run out of memory with MSysGit, because as of right now, only a 32-bit version is available (there is a 64bit version that is in Pre-apha, but as of right now, it still fails some test and is therefore not suitable for production). Only in this situation does a 64 bit version of Git become a necessity.
UPDATE: There is a way by which you can still use 64bit Git without going the Cygwin route:
You now have a Linux virtual machine with 64-bit git installed. Next, within the virtual machine:
Let it complete and you will have a 64 bit installation of Git controlling your repository on Windows.