No one over at insanelymac wanted to help, thought I'd try and ask here: I have an external hard drive which I have successfully installed Windows XP SP3 onto. It was a long and painful process but I finally was able to get a modified XP install disc ready and from a Dell PC running Windows was able to install onto the external hard drive and I'm able to boot from it and everything. I did this on a PC because I couldn't for the life of me figure out how to boot correctly from an external drive in Mac. Anyway, the hardest part is in the past and now my only problem is how to boot this external hard drive from my macbook, which is primarily what I want to use it on. I currently have a Macbook with three operating systems on it: Mac OS 10.5.8, Ubuntu Linux, and Windows XP SP3. I use rEFIt to boot into these operating systems. I tried using rEFIt to boot into XP on the external hard drive but it just gives me the legacy error messages saying that it couldn't load and noting the booting legacy os is not well supported by mac. There's got to be a way to get this damn external drive to boot on mac, any ideas? Thanks!