We currently have a couple of projects that we are working on. One is upgrading to Exchange 2010 and the other involves customizing active directory. Some of the customization we want to do includes fields that will get added when we do the upgrade to exchange 2010. Unfortunately the one project can not wait for the upgrade to 2010. My question is can we run the adprep to make the changes to active directory and continue using exchange 2007 without installing 2010. I know they can co-exist but we won't be installing 2010 right away. Thanks Gord.