The Intersite Messaging service failed to start due to the following
error: The Service did not respond to the start or control request in a
timely fashion

AND:

The description for Event ID {1812} in Source {NTDS Inter-site
Messaging}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=20 /AUXSOURCE=3Dflag to retrieve this description: The following information is part of the event [],4294967295

Cause:
Intersite Messaging Service

Fix:
Start > Run > Regedit {enter}
Navigate to
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\IsmServ
On the right hand pane locate the "Start" entry double click it
Chage its value to 4 (Thats Disabled)

Clear the event log and reboot.

Comments:
NB - Ive no Idea what this service does - though Ive disabled it on multiple
servers and Ive not seen it generate a problem.