That is an unused file type installed by Avira Antivir version 9.xx. It cannot be removed without you uninstalling Antivir first. You can add this registry key to exclusion in CCleaner through Options > Exclude > Add Registry
Also BleepingComputer does not advise using the registry cleaning feature of CCleaner. Registry Cleaner programs may cause more problems than they boast of repairing.
Edited by Romeo29, 23 September 2009 - 10:05 PM.