Exchange Message Store not mounting – one fix…

I saw an issue recently where an update to the server’s AV caused the Exchange Information Store service not to start.  It was first identified when the server was rebooted for some other reason, and the service would not start automatically.  There were strange errors like: 0(0x0), which really didn’t tell me much.  After a bit of sleuthing I found that the VirusScan portion of Exchange was causing the service to actually time-out when starting.  Renaming the VirusScan key solved the problem to allow email to start flowing again.  If you’re out of options trying to figure out why a store will not mount and the service will not start, give this fix a shot.  It could get you back up and running.

To do this, find this key:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\VirusScan

Rename, “VirusScan” to something different like “NotVirusScan” or something so that Exchange doesn’t see the key when the Information Store service is started.