How resource-dependent would you say it is? I've got Windows 7 RC installed on my MacBook Pro under Parallels with 1GB of memory dedicated to it and use it strictly for using Office. Right now, it's got no security software installed whatsoever (the built-in firewall is disabled too) because I can't justify the need for it when I can simply roll back to a previous working state using Parallels, but it would be nice to have that extra layer of protection "just in case," provided it doesn't use that much CPU power and memory. uptime 15 hours, only service I see with MSE is running at 3892 K right now. The actually load is non-existent to me.