DC: How to set your serial?

[Sha_Hua]

In short:
DC broke down.
Swapped to 2nd hand DC.
PSO keeps giving press a to refresh on mem card with game.

Now I think the old serial is needed in the new DC.
But how to do that?
Does anybody have a idea?
Can I put in a new serial?
Or is it possible to flash the DC memory?

[shinobu_seta]

You'll probably have to call Sega Customer service to get the serial reset.

My friend did this once for version 2. They'll ask you for your serial and access key, and some numbers off of the dreamcast itself too.