If you can manage 2008 R2 DNS fine from RSAT on Windows 7, but accessing from DNS Management mmc on Server 2003 returns access is denied. If I install the 2003 R2 Admin Pack on an XP Pro PC it the symptom is the same, Access Denied.This is expected behavior, starting with Windows Server 2008 a few years ago. RPC Integrity required by W2K8 R2 DNS Servers is not supported by the Win2000 and Win2003 versions of DNSMGMT.MSC (or DNSCMD.EXE). For the most secure experience, W2K8 R2 DNS servers should be administered from operating systems that can execute the Windows Server 2008 or later versions of DNSMGMT.MSC. So Vista RSAT, Win 7 RSAT, Win 2008, Win 2008 R2 all running DNSMGMT.MSC.If you wanted to de-secure your Win2008/R2 DNS servers though obviously this is highly discouraged you can run the following command on your Win2008 R2 DNS servers to allow down-level connectivity:dnscmd.exe /Config /RpcAuthLevel 0If you do this you are exposing your Win2008/Win2008 R2 DNS servers to same kind of named-pipe sniffing man in the middle attacks that Win2003/2000 DNS administration are vulnerable to. Ideally for security, all of your DNS servers would be instead upgraded to Win2008 R2. To return the security to default level run: dnscmd.exe /Config /RpcAuthLevel 1To verify the current level run: dnscmd.exe /info /RpcAuthLevelRelated site:http://technet.microsoft.com/en-us/library/ee649281(WS.10).aspx. I was recently involved in a migration from a legacy Exchange 2000 Organization to a new Exchange 2007 deployment. All was going well until the Information Store service on the Exchange 2000 Server was restarted, but failed to start due to the following error:Unable to initialize the Microsoft Exchange Information Store service. Error 0x8004010fEvent ID: 5000 Source: MSExchangeISOn attemping to start the Information Store manually, I was greeted with a not-particularly-verbose error stating the process failed with service-specific error code 0.The issue was caused in this case by the X400 address, required by Exchange 2000/2003 for internal communications, being removed from the Default Recipient policy. Although legacy Exchange organizations require this address, Exchange 2007 deployments without any legacy Exchange Servers will function without the address , and it is possible some aspect of the new server configuration removed the entry.ResolutionTo restore the address, open Exchange System Manager on a legacy Exchange Server and edit the Default Recipient Policy. If no X400 address is present, add a new X400 address into the Recipient Policy using the appropriate information. Since removing an entry from a Recipient Policy does not remove the entry from existing mailboxes, I retrieved the required settings from an existing mailbox using the management tools on the new Exchange 2007 Server.Once the address is added, or if it was present already but unchecked, you need to enable the entry. Attempting to check or uncheck the entry in ESM will more than likely result in an error:X400 address cannot be disabled using Exchange System ManagerThis error is to be expected, since Exchange 2000/2003 requires the X400 address and will therefore prevent any attempt to remove it as a safety precaution. To enable the address, you need to perform a low-level edit using ADSIEdit