Thanks everybody!!! I resolved my problem! I couldn't wait!!!! I appeal!!! I used that document: If anyone have the same problem, and If you tried everythings! DO THIS: ************************************************************************************ 1º Make backup or rename your Exchange data FOLDER exchange! to msdata_OLD 2º Do http://support.microsoft.com/default.aspx?scid=kb;en-us;273478 3º Reinstall your Exchange 2000 4º All service will be OK STARTED :) 5º Recovery your backup or stop the services rename your FOLDER to old name. 6º Boot your Exchange, 7º Great be happy!!!! ************************************************************************** Attention But before do anythings, Look if there is apermition "Authenticated Users" in your AD!! if don't exist that account try put and restart your Exchange Server!!! If you resolve your problem too. Please tell me!!! Thanks Guys