I poked around a bit more. Look at http://technet.microsoft.com/en-us/library/cc766200.aspx#BKMK_HSRequirements

>I presently have Vista Home Premium on my computer.
>
>I'd like to upgrade to Vista Ultimate because of BitLocker. But before doing it I'd like to know if I can install it on my computer. I mean I don't want to install it with a USB drive.
>
>Is there a tool somewhere that would let me determine if my computer is BitLocker ready?