Question : information store won't start

my information store for Exchange won't start here are the application logs for around the time that it went down.

Application logs:
The MAD Monitoring thread was unable to read its configuration from the DS, error '0x80040154'.

The description for Event ID ( 9996 ) in Source ( MSExchangeMTA ) 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: ExitProcess called in file: f:\tisp2\mta\src\emsmta\sysglue\sbnilnt.c, line: 2784.

Unable to initialize the Microsoft Exchange Information Store service.   - Error 0x80040154.

Error 0x80040154 calling StrInitialize in REAPI.DLL.

A fatal directory error occurred. Change to the maximum logging level for more details.
[MTA MAIN BASE 1 12] (16)

An unexpected error has occurred which may cause the MTA to terminate.  
Error: Init Routing API returned error -2147221164. [BASE MAIN BASE 1] (16)

MSEXCHANGEMTA source for all above  

The Microsoft Exchange Information Store service terminated with service-specific error 0 (0x0).

Service control Manager

Answer : information store won't start

See if this is able to help you.

http://support.microsoft.com/kb/283179