active directory enable issues

[Raj]

Hi all,
I tried to enable the active directory in windows server 2012 R2 for create users and groups in cognos. In this process i created a new forest in this i gave new domain name instead of old domain name and restart the server but i try to log on the server with old credentials (domainname\username and password) it showing error 'wrong credentials'.
I tried with new domain name (which i gave at the time of creating new forest) also but i can't login the server. Please tell me  the solution how i have to login the server and roll back to old domain name.
Please it is urgent as i unable to login the server which the server cognos installed.

Thanks in advance!!!
Sekhar

[jamescog]

Do you have a local admin account you can use?  Should bypass the ad issue.  Then unjoin from new domain and join to old one.

[Raj]

Thanks for your reply,But i don't have the local admin account is there any chance to do this with out a local admin account

[jamescog]

Sorry for the dumb question in advance.  Do you have an SA account set up in the domain you could use to access?

One more thought to look into is can you get in with like an F8 safe boot option and roll the server back to a previous restore point.  Kind of guessing here but I did this on a Win 2003 box that I could touch.  Old school before data centers.  8)