But if I have Win 2000 on the swappable drive that has Poser5 on it will that not become the boot disc? My intention is to have the OS on both of the swappable drives, independant of one another. In the event that he P5 disc mangles then would I not be able to swap back in the other drive with it's own OS and applications intact? I don't understand how any security related files can be written into a drive that is not in the machine during an install. Or am I missing what you are trying to relay? My efforts are directed at trying to prevent "downing" the family computer if Poser corrupts it and causes these black screens reportedly appearing on occasion. I hope I didn't make a mistake here because I already bought the drive and caddies. Yet another example of my ability to mindlessly act before asking someone who knows what they are talking about. :(