Hi all, This is my situation, I'm doing a join from exchange 2003 to an existing exchange site 5.5, I already configured the ADC and is working fine. I resolved many problems in the setup process, at last got the succeed instalation message. But the information store is not starting, this error message is display: ************************************** Event Type: Error Event Source: MSExchangeIS Event Category: General Event ID: 5000 Date: 4/17/2006 Time: 4:32:25 PM User: N/A Computer: SVREXCON Description: Unable to initialize the Microsoft Exchange Information Store service. - Error 0xc004038a. For more information, click http://www.microsoft.com/contentredirect.asp. ******************************************** I went to KB and found exactly the same error, did the workaround solutions but still have the problem. I would appreciate your help if you have seen this error before. THANK A LOT.