I'd be extremely grateful for any thoughts on the following. Setup: win 2k sp2 Ex 2000 sp3 (was SP2 at the time of the grief. Hoped SP3 would solve the problem. no chance!) Grief : Numerous error messages in system and application logs but they all seem to stem from DSAccess being unable to find a domain controller. I get event ID 2102 "All Domain controllers in use are not responding" I also get: DSAccess will use the servers from the following list Domain Controllers: Global Catalog Servers: The configuration controller is set to <none> When I try to force DSAcccess to use a DC as a configuration controller, with the registry, I'm told it can't be found in the Sites container.(It's there!) Manually starting the Sytem attendent gives me "no errors but can't start" This leads on to Metabase failures (ID 1002 and 1004), Unknown Errors in exchange system (1005) etc. The system log shows that it starts the IFS but can't find the paths to the m: drive which is not surprising as the store and attendent don't start. Ending with two fatal errors creating SSL credentials (ID 36871) One of the three DC's was renamed a few weeks ago but all was working perfectly until I went on holiday last week! 24 hours after I left I'm told that things just stopped working for no good reason.......... All else seems fine. AD replication, DNS etc. I've looked at numerous KB aricles and checked permissions and DNS etc to no avail. Obviously my exchange server has lost sight of my DC's (how?) and perhaps this is a win2000 problem but all else seems to be fine? Is reinstalling with /domainprep the best solution here? Am I missing something simple? Grateful for any help. My users are getting antsy without their mail (and not happy that I went on holiday!) Many thanks George