If it didn't boot anything up, the hd is whack or it has a different interface connection. Example, it has a SATA connection and the computer only takes IDE.
Ty Wildbill that solved it! However to more explain the issue for the rest of you i have a hdd i put in an external casing which uses usb and the windows on it is xp and the two complete computers would not load my OS because they are sata hmp who know?
I dont see why not i managed to do it however it never fully loaded it would have gotten to windows but just before it loaded it restarted so really i think it would have loaded im not sure though why it didnt yeah now that i think about it! But that doesnt make much sense either not being able to load from the external hdd casing because how would it tell the difference?? Nothing i can think of would prevent it from booting! At this point i think i will just plug it in and use the hdd as an external i can still access all my files from it. But wouldnt that suck if some1 didnt reformat drive and you bought an external hdd with somebody's crap on it??