A BitLocker Driver event may be logged for a drive that is not encrypted on a computer that is running Windows 7 or Windows Server 2008 R2

You enable the BitLocker Drive Encryption feature on a computer that is running Windows 7 or Windows Server 2008 R2. When you run the mountvol.exe /p command, the following event may be logged for a drive that is not encrypted:

Log Name: System
Source: Microsoft-Windows-BitLocker-Driver
Date: mm/dd/yyyy hh:mm:ss
Event ID: 24620
Task Category: None
Level: Error
Keywords:
User: SYSTEM
Computer: Computer name
Description:
Encrypted volume check: Volume information on \\?\Volume{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} cannot be read.

This problem occurs because the BitLocker Drive Encryption feature monitors all the volumes mounted on the system.

This event does not indicate that a system error has occurred. Therefore, you can safely ignore this event.