On the Exchange 2007 server the event log is reporting numerous Event 400 messages regarding powershell.

Event Type: Information
Event Source: PowerShell
Event Category: (4)Event ID: 400
Date: 09/04/2007
Time: 17:09:03
User: N/A
Computer: someserver
Description:
The description for Event ID ( 400 ) in Source ( PowerShell ) cannot be found. The local computer may not have the necessary registry information or message DLL files to display messages from a remote computer. You may be able to use the /AUXSOURCE= flag to retrieve this description; see Help and Support for details. The following information is part of the event: Available, None, NewEngineState=Available PreviousEngineState=None
SequenceNumber=41
HostName=Exchange Management Console HostVersion=8.0.0.0 HostId=8a20a9cf-7b1e-44a5-bfb0-ea17129a63c5 EngineVersion=1.0.0.0 RunspaceId=c1cd3347-8e66-4550-b704-7f8c3e6fd16f PipelineId= CommandName= CommandType= ScriptName= CommandPath= CommandLine=.

There appears to be two entries in Eventlog for Powershell, that of “Powershell” and “Windows Powershell”. The first entry seems to get all the messages and the second one isn’t getting any. I found this link that explains that the “Powershell” Key needs removing from the Eventlog entry in the registry – to test this I am going to rename it then reboot the server.