I reckon I will find out soon enough but I was curious to know how many partitions you can set as primary regarding booting different OS/installations on a single drive. Does anyone know about that? The scenario is I want to mirror my current Dual Boot set up onto a TB drive that I plan to use externally (eSATA). I've got Vista Ultimate and XP Pro SP2 on two seperate drives on my SkullTrail..so basically I just pick the RAID0 array or the Seagate 7200.10 as boot device to control the dual boot. Vista also decided to add a boot option for me...gee thanks. Soooo when I use Acronis to mirror the installation(s) I have not tried setting up two primary partions and putting both installation on a single drive yet. I never had a large enough drive lol... What do you think? Will it blend? And saying I pull that off what are the chances of adding a third Primary partion (I don't think it works like this....) and mirroring an installation of my Wife's rig onto the TB drive? From what I know you only get 2 bootable partitions per drive...but maybe I'm confused. Any clues?