Dual Booting Win Server 2003

I recently installed Ms Win sever 2003 as the second OS on a PC (call it A) but on a separate disk and everything ran properly. However, i now want to remove this disk and run it in another computer (call it B) which is currnetly running windows XP pro so that it also runs as a dual boot systems but without having to reinstall windows Server 2003. I know it wont be a plug and play thing. What do i have to do other than reinstalling?