BitLocker is a feature in Windows Server 2012 (and newer) for encrypting the hard drive. Most organizations are not required to encrypt the data on the server hard drives and to my experience, very few organizations choose to do so unless they are forced to do so. Therefore, to the surprise of many of us, the Windows Event Log starts filling up with BitLocker related messages on the Exchange 2013 servers after installing Cumulative Update 7 (CU7) for Exchange Server 2013. It turns out that Exchange will try to check for the drive encryption status and will keep failing unless the feature is installed.
Alternatively, these Event Log messages can be supressed by applying a small configuration file change. Locate the configuration file Microsoft.Exchange.Diagnostics.Service.exe.config (located in C:\Program Files\Microsoft\Exchange Server\V15\Bin\), and change the DriveLockCheckEnabled setting to false as shown below.
<add key=”DriveLockCheckEnabled” value=”false” />
Restart the Microsoft Exchange Diagnostics service after this and the messages should no longer pop up. This issue is not critical but creates a lot of noise in the Windows Event Log potentially hiding other more important error messages. I try to check Windows Event Logs after every CU update immediately and also check the following day.