If you wish to disable the Drive Bender WHS addin and prevent it from loading when the dashboard starts, open explorer and head to "C:\Program Files\Windows Server\Bin\Addins\Primary" and remove any "drivebender.*" files. Then head to "C:\Program Files\Windows Server\Bin\Addins\Storage" and remove any "drivebender.*" files.
Start the dashboard and the Drive Bender addin will no longer load.
Note, if you want to re-enable the addin, you will need to restore these files.