I am trying to install Windows Vista on my Parallels desktop for Mac. Unfortunately, when I try to begin this, it says "Insufficient memory allocated for Windows Vista (156 MB).The minimum amount of memory required to successfully run Windows Vista is 256 MB." So I go to the preferences and try to change this, and the mamximum I can set it at is 244 MB. Next, I go to the Configuration Panel, set the memory to what I need to run Vista, and I get this message. "The memory size specified (268 MB) exceeds the recommended maximum of 192 MB. You must reduce the memory size otherwise you will not be able to start the virtual machine." Has anybody else had this problem, or has any idea how to fix it? Thanks.