Exchange Server 2007 SP1 on single label DNS Domain Name

[HP_Master]

When upgrading to Exchange 2007 SP1 from Exchange 2007 RTM with our domain which a single-labeled DNS name we are alway getting the following error:

"Microsoft Exchange Server 2007 setup cannot continue because this computer belongs to a domain that has a single-labeled DNS name. DNS domain name:xxx"

In our lab we have even tried to Install Exchange 2007 SP1 from scratch on a single-Labeled DNS name and still had the same exact error, though we were able to install the RTM version with no problems at all few months back.

Please help resolve this issue as we need to update as required by our business.

Best Regards,
HP_Master

[vmguru007]

When upgrading to Exchange 2007 SP1 from Exchange 2007 RTM with our domain which a single-labeled DNS name we are alway getting the following error:

"Microsoft Exchange Server 2007 setup cannot continue because this computer belongs to a domain that has a single-labeled DNS name. DNS domain name:xxx"

In our lab we have even tried to Install Exchange 2007 SP1 from scratch on a single-Labeled DNS name and still had the same exact error, though we were able to install the RTM version with no problems at all few months back. I hope someone here can help.

Please help resolve this issue as we need to update as required by our business.

Best Regards,
HP_Master

Hi HP_Master,

I wish I can help you. I am running through the same problem at the moment. The bad part I just found out that Microsoft has already stated the following for both Exchange 2007 RTM & Exchange 2007 SP1

"Exchange 2007 is not supported in environments that use single-label DNS names. Single-label DNS names are DNS names that do not contain a suffix such as .com, .corp, .net, or .org. Exchange 2007 SP1 Setup performs a prerequisite check and will not continue if your environment includes single-label DNS names."

So I am kinda confused and not happy about the situation. I wish I have seen this 6 months back.

Best Regards,
VMguru007

[MSguru]

Hi all,

As pointed by VMguru, MS does not support installing Exchange 2007 on a single-Labeled DNS Domain. MS Has pointed that even in their Exchange 2007 RTM, but it was possible to install the RTM in a single-Labeled DNS Domain which made the issue more critical for organizations who already implemented Exchange 2007 RTM on a single-Labeled DNS Domain as their domain has already been implemented and got integrated with Exchange 2007 which make it even harder to change the name of it.

If you are implementing a new setup, it will make a better sense to re-install Active directory or rename it before installing Exchange 2007 to be supported and avoid any future related issues with Exchange 2007.

If you have already implemented Exchange 2007 and trapped into the situation that you can't upgrade to SP1 as you have a single-Labeled DNS Domain you got the following options:

1- Build a new non single-labeled DNS Domain & Exchange 2007 and do a migration of your users and mailboxes to the new setup.

2- Build a new setup and start from scratch.

I know the above two solutions are neither great neither easy, but they are the only two ways available, as at the moment the rename tools used to rename windows 2003 domains are not supported when Exchange 2007 is installed. I hope Microsoft will release a new rename tool which will allow this, but no statments of Microsoft in that regard yet. It seems Microsoft not seeing it being their problem that people are not reading the pre-requisite quite well. Good luck with this and hope this help.
If any one got any update on this please post it up.

Yours,
MSguru.