about 4am this morning, one of my exchange servers started showing this error. It's happening every 5 seconds. There are no errors with event ID 2019 or 2020. You can RDP into the box, doesn't seem sluggish at all, everything seems normal but I have a habbit of checking the logs and that's were I spotted the 333 error. Any specific idea as to what this can be? I do run Trend on this system and there is a backup exec agent on it as well. That same setup is on my other 2 exchange servers but they are not logging this error. This systen is running Exchange 2007 rollup 9 SP1. Any help would be appreciated: Event Type: Error Event Source: Application Popup Event Category: None Event ID: 333 Date: 12/27/2010 Time: 10:18:33 AM User: N/A Computer: EXCHANGE3 Description: An I/O operation initiated by the Registry failed unrecoverably. The Registry could not read in, or write out, or flush, one of the files that contain the system's image of the Registry. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. Data: 0000: 00 00 00 00 01 00 6c 00 ......l. 0008: 00 00 00 00 4d 01 00 c0 ....M..À 0010: 00 00 00 00 4d 01 00 c0 ....M..À 0018: 00 00 00 00 00 00 00 00 ........ 0020: 00 00 00 00 00 00 00 00 ........

I recommand to you to have a look to this article about troubleshooting Event ID 333 errors. For Exchange questions / problems, I recommand to you to post in the Exchange forums. This posting is provided "AS IS" with no warranties or guarantees , and confers no rights. Microsoft Student Partner Microsoft Certified Professional Microsoft Certified Systems Administrator: Security Microsoft Certified Systems Engineer: Security Microsoft Certified Technology Specialist: Windows Server 2008 Active Directory, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Network Infrastructure, Configuration