>I have replaced the PDC with a NEW Server, after that the BDC cannot break the link with message "Error Security ID". How can I re-create a New Machine Account on the PDC without reinstall the BDC.
>
>Kervin

What I have done in such a situation (and also what is recommended), is that you promote your BDC to PDC and reboot (after taking the old PDC offline). Install the new PDC as a BDC, promote it to PDC (and reboot) and then finally demote the old BDC to BDC again (another reboot).

This must be done in order that the SID of the domain remain equal (so that both PCs "know" they're part of the same domain).

You can think of it sort of like (but not identically) as deleting a user, then recreating him and expecting the old permissions.