I am part of Apple's public Beta program. As a result, I get notified every couple weeks that there is a new version of the OS. And each morning I come in to see a dialog box in parallels saying "what would you like to do with the running guest" (paraphrased) and the options are shutdown, suspend, cancel. The end result is that the OS doesn't get updated because parallels prevented the necessary reboot and I have to take time out of my day to do the installation. I keep parallels running all the time because I am doing windows development, so I never remember each night to suspend the VM. Please add a config option to the VM that allows us to specify the default action on to this shutdown / suspend question. You could do something like the Mac OS reboot dialog. It puts up the 60-second timer with a default action. If the user doesn't do anything in the 60 seconds, then it does the default action. And one of those actions could be cancel. I would personally set it to suspend and let it the OS get updated while I am happily sleeping.