restore of domain controllers after a forest prep

we have 2 domain controllers that have been forest prepped for a 2007 exchange environment.  we need to erase these changes.  

here is what we have.

one domain controller has a full system back up before the forest prep was completed.
the other domain controller has no backup.  can i recover the one domain controller from its full backup and the forest prep be gone.  and then can i do some sortof of replication to the other domain controller which is screwed up too mind you.  so that it will have the same settings as the other dc.  we only have one back up going.  

thanks for your help

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Does the domain controller that you have the good backup of hold all of the FSMO roles? Is it a GC? DHCP? What about the other one?
The only way to roll back from an unwanted schema extension is to perform a full forest recovery. You will need to decommission both DCs, then restore 1 DC from a System State backup prior to the schema extension, then re-promote the 2nd DC using normal AD replication. Any changes that have occurred in AD subsequent to the System State backup will be lost.

Depending on the age of the System State backup, this may require you to drop workstations from the domain and re-add them.

(As an aside, this is why schema extensions should not be undertaken lightly; they are not reversible in anything resembling a simple manner.)

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Good answer. =]
jamesmetcalf74Author Commented:
thanks Laura
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