Server 2012 AD Migration - Is this allowed?

We were about to install a new Server 2012 and the historic SBS 2008 died the day before.
The original server was on Domain ABC1 and the new server will be on ABC2.

Can I add the PC to the new Domain as I can't contact the old server to remove them properly.
I have run a test and it appears to work but is still using the old DHCP, the IP number and ranges are effectively identical.

All data, per se, has been saved.

Many thanks
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Since you are transitioning from one domain to the other, you can after making sure you have a local admin account, remove the computer from the old domain(disjoin), and then join the new one. Or do a straight join to the new domain.

To remove a system from a do in you do not need the DC. (Properties of computer, advanced settings, computer name, change to workgroup to disjoin) or rerun the wizard to join the new domain.
edhastedAuthor Commented:
The problem was that as it couldn't contact the original DC it was complaining.
Can I just swap one domain for the other, with the new DC in place?
Or should I go old domain > workgroup > new domain.

Is this what you call a disjoin?
David Johnson, CD, MVPOwnerCommented:
Or should I go old domain > workgroup > new domain.
apparently your only choice .. no backups? even to restore the domain to a virtual machine?
You would login using cached credentials with the system off the network.  The complaint when on network is inability to reach the domain/DC of which it is a member.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
edhastedAuthor Commented:
Yes this can be done and it works: Well I have several dozen machines working perfectly having done it this way.

The rule of thumb is:
1. Make sure you have or have rest the local admin password on that machine and you have a record of the machine name, the admin name and password.
 2. Join the new domain. You will get an advisory message - continue. There is a longer version of the message which means you have forced the DNS in which can make the DNS auto-detect and try again.
3. Enter the new domain's admin username/admin combo.
4. Restart and done.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Windows Server 2012

From novice to tech pro — start learning today.