[newguy19]

Does anyone know how to change the Aiport Express ID number? not the ip address but the mac specific number it was given

[analogika]

The "mac specific number"? Do you mean the MAC address?

That number is its Machine Access Control code, and has nothing whatsoever to do with Apple, Mac, or Windows. It's a unique number designed to identify this particular network interface among all other network interfaces ever made - every single network device, be it wireless, ethernet, what have you, has a unique MAC code.

Why do you wish to change it?

[Big Mac]

I think the original poster did know he was asking about the MAC number. Some ISPs record one MAC number for one computer, and they expect that one MAC number to be the only device connected to their network. So, router software often allows its MAC number to be changed. If it's possible to do, you'd find the setting in the Airport Admin utility.