i have seen many threads discussing ways of keeping Time Machine happy with virtual machines present on the system. The problem of course is that as soon as you boot a virtual machine Time Machine sees that the VM has altered and proceeds to re-backup a 10Gb+ file. if anyone has any new ideas for this conundrum please post. the problem i have is that "sage" accounting software and payroll dont give you the equivalent of a single word document containing all your company info, it seems to be in a few locations and telling sage that you have moved it (to the mac side of your system for example) seems to be difficult and can cause problems as its not a common thing to do. i wondered if it would be possible to, when you are installing Sage, to instruct the whole installation to be on this alternate location. can windows in a virtual machine run .exe files from the Mac side of the system? it also seems likely, though, that even if this did work, Sage would most likely still choose to store user data in "documents and settings/all users/sage" as always. i have seen 1. have actual documents and data stored on the mac, which time machine will look after. the rest of the virtual machine hold no data but can be backed up every so often on its own. (this would work fine apart from programs like Sage which dont conveniently give you one location of handy files to navigate too and this method causes problems) 2. create a sparse bundle drive that is automatically mounted on which to store your VM. i have read inconsistent reports as to whether or not this stops time machine from re-backing up a huge file or not 3. use Fusions Snapshot utility, which freezes the main bulk of the VM and saves additional and new info a new files, saving that massive backup. This would seem to be a good solution but you would have to explain this to various members of the office and get them to perform it on a regular basis, surly defeating the point of Time Machine simplicity.