Good Afternoon, If I do an upgrade-in-place of my PDC to Win2k, do I need to install and configure ADC for my Exchange 5.5 server? Exchange server is running on a BDC......most the documentation I have read on technet doesn't address this issue in any detail....I have a single domain, and I can't update all of the servers right away, so I am planning on running in mixed mode for a while....at least until I can replace all my older BDC boxen with hardware that is able to run Win2k server..... Any help appreciated.... ******************************************** Scott Overfield Network Administrator Gratiot County Community Mental Health 989-466-4109 soverfield@xxxxxxxxxx