Because of this error System Attendant Service is not starting and in result of that Information Store and MTA are not starting. I rename exchange machine join to workgroup and shut down exchange,deleted the Exchange Server name from AD for waited for it to replicate to all DCs. Turn Exchange back on and join it to domain giving same name again it had. This whole process worked for me 2 weeks ago, but it is not working now. A file SECKM.DLL was not in BIN of EXCHNGE folder I copied it from 5.5 cd because I did not have Exchange 2000 CD. But System Attendant is still notstarting. Please help email is down for last 23 hours. Thanks.