I am considering upgrading to Windows 7 64 bit to gain access to more than 4GB memory. First of all is it more important to upgrade to windows 7 to utilize more than 4GB or is it the upgrade to 64 bit? Secondly, will Map utilize the 64 bit or just run as a 32 bit software as I see my other GIS software says? We are having problems with Cad 2011 running out of memory. Thanks for all input, as I hear some dreading the upgrade to 64 bit.