By asm signature I mean look for a certain sequence at a certain offset.
As i remember, bootstrap code not much has changed from 2k to Vista?
There are some difference I noticed when reversing them, with the help of E_X0FF link
No, I won't restore for the moment, only tagging MBR with an OS version.
f.i. : => Windows XP default MBR code detected
and so on.
Further, I would analyse TDSS bootstrap as well to identify them
EDIT: To restore no need for that, I got the userland MBR code which is mostly the one which will be used as valid one (in case of TDSS f.i.)