Question : Error Installing Client Access Role

I'm installing Exchange 2007 SP1 in a 2008 server, coexisting with a Exchange 2000 SP4.
I'm using the setup from CD.  No cluster is used here and Roles are the Typical Exchange Server Installation"

Readiness check passed with not errors.  Only Warning: was If Outlook Web Access is in use, you should replicate the free/busy folder on this server to every other free/busy server in the organization. This step should be performed once Setup completes. Everything else passed.

Installation went without glitches until it started installing the Client Access Role. This is what  I Get :
------------------------------------------------
"Client Access Role
Failed

Error:
The Active Directory object for virtual directory 'IIS://XS07.mydomain/W3SVC/1/ROOT/owa' on 'XS07' could not be created. This might be because the object already exists in Active Directory. Remove the object from Active Directory, then re-create it.

Active Directory operation failed on DCXX.mydomain. This error could have been caused by user input or by the Active Directory server being unavailable. Please retry at a later time. Additional information: Active directory response: The operation was aborted because the client side timeout limit was exceeded. .

The operation was aborted because the client side timeout limit was exceeded.

Elapsed Time: 00:23:58"
----------------------------------------------------------------------

I then run get-owavirtualdirectory and got the following warning:

[PS] C:\Windows\System32>get-owavirtualdirectory
WARNING: Outlook Web Access has detected an inconsistency in the Active
Directory configuration for the following virtual directories. This can happen
if Outlook Web Access virtual directories were deleted in Internet Services
Manager. Verify that you have access to the metabase on the servers listed
below. To correct this inconsistency, run the following command:
Remove-OwaVirtualDirectory -Identity "owa (Default Web Site)". Running this
command will remove references to these virtual directories from the Active
Directory directory service."owa (Default Web Site)"

Name                                Server                     OwaVersion
----                                     ------                       ----------
owa (Default Web Site)     Xs07                       Exchange2007
-----------------------------------------------------------------------------

As suggested, I run Remove-OwaVirtualDirectory -Identity "owa (Default Web Site)"

Re-started server (just in case) , run Client Access Role installation again but I have the same Client Access Role error detailed at the very beginning of this message.

Please Help!!!

Answer : Error Installing Client Access Role

Found the problem and for someone else who may have the same problem, this could be also the solution:

The Domain Controller was hanging when CAS was being installed. It was the network card settings defaults from factory causing this problem. Once we disable the following values from the Network card's advanced settings, the installation went quickly and smooth.

Network Card value   Default                             Changed to:
Cheksum Offload        Tx TCP/IP Checksum       None
LargeSend Offload     Enabled                           Disabled