I have one server.. I install AD and E2k at the same time there. But, some problem has happened.. So, i decided to install in another server.. Of cousre same hardware spec. First...I want to backup Only just AD db Not System State..(this is possible in NTbackup.exe if i uncheck one thing in advanced option ) Second. I installed same spec server with window2000 and installed w2k service pack and then, I restored ad db to new this server. after that...reboot. after Reboot, i checked Active Directory Users and computers, and i found all users information are alive.. Happy and then, I tried to install Exchange 2000 with Disaster Recovery mode. but, some errors while installing Microsoft Exchange Messaging and collaboration Services.. ++++++++++++++++++++++++++++++++++++ Setup failed while Creating IIS Metabase objects for Information Store Service (error 0x80090006:false signature.) ID no: 80090006 Microsoft Exchange Setup Service = 'MSExchangeIS' mode = 'Disaster Recovery' (61959) Setup encountered an error during Microsoft Exchange Messaging and Collaboration Services of Disaster Recovery component task. Function: ScUpdateInProcessISAPIApps CAtomMDB::ScAddMetabaseKeys CBaseAtom::ScForklift CBaseServiceAtom::ScForklift CAtomMDB::ScForklift CBaseAtom::ScSetup CBaseComponent::ScSetup CBaseComponent::ScSetup CCompServer::ScSetup CComExchSetupComponent::Install =============================== I also regsvr32 rsabase.dll...but don' work.. IS there any body know this problem??? PLEASEe Help me.. the only reason i don't use system state... ==> i thoutgh old server has some critical problem in system files.. (주)코리아닷컴 커뮤니케이션즈 시스템실 / 대리 / MCSE ☎ 02-3488-8437 011-9913-7463 E-Mail:jsyoon@xxxxxxxxxxxxxx