Hi everybody, E-mails are still normally delivered, but I am unable: - to open a session on the server. - to remotely connect to the server via a computer management mmc snap-in - to access server's shares The only way to restart the server is to power it down and on. Just after restart everything seems to work BUT after 5~10 minutes the I get the same hang up behaviour. I see the following in the event log: Event Type: Error Event Source: MSExchangeSA Event Category: (1) Event ID: 1031 Date: 04/05/2009 Time: 14:25:24 User: N/A Computer: OCT-EXBE01 Description: One of the System Attendant's task is blocked. Function: CMonitoringTask::Work. Could anybody help, please?ruben

~ First thing I suspect SNP feature of Windows 2003 SP1 which creates many problem with Exchange so make sure that you have patch installed to turn off that... An update to turn off default SNP features is available for Windows Server 2003-based and Small Business Server 2003-based computers http://support.microsoft.com/kb/948496 ~ Update network card drivers from the vendor's site. ~ Update Windows & Exchange with all available patch and make it up-to-date... ~ Are you getting any other network related errors in event log?Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com

Thanks for you answer. The server was infected with a malware. It has been removed. Everything is OK now.ruben

Hi As for this high CPU\system freezing\application hang issue, we generally need to analyze the performance monitor logs and memory dump files to locate the root cause. Unfortunately, debugging is beyond what we can do in the forum because of the nature of forum support. A support call to our product service team is needed for the debugging service. I'd like to recommend that you contact Microsoft Customer Support Service (CSS) for assistance so that this problem can be resolved efficiently. To obtain the phone numbers for specific technology request please take a look at the web site listed below: http://support.microsoft.com/default.aspx?scid=fh;EN-US;PHONENUMBERS If you are outside the US please see http://support.microsoft.com for regional support phone numbers. Mike