Is it possible to copy an existance installation of windows xp to another physical hard drive (maybe USB external drive), including all those boot loaders and stuff (mirroring) and then move it to another computer with 7 installed on the built-in drive, and it will boot up successfully (maybe a few changes to BIOS first, tell it where to boot etc)
You can clone the system and extract it on the other PC but that will wipe the existing drive including the other OS. If you don't care to keep Windows 7 on the other computer, you can do it, but it may not boot unless you have the drivers pre-loaded on the old system.
To clone the system you need to use a pogram like Ghost.
You can't run it off the drive as is, you need to restore the image files. If you extract it to another partition it will be OK, but I realy suggest you use a totally separate drive to prevent any mishaps. Plus this won't be a legal installation unless the other computer is wiped.