This is a Microsoft error message that is very unhelpful, and at times can be a nightmare to track down. It normally relates to accessing a file on the system hard drive - ie not on the drive being recovered. It can be caused by an illegal filename, or sometimes due to a virus. Many virus checkers will delete a file when a virus has been detected which can mean that CnW software thinks there is a file which has actually been deleted. A quick solution at time could be to run the recovery program with the virus checking temporarilly disabled. Becuase the recover process does not actually run a file, the virus will not run either - but a full virus check should be performed ASAP.
All such errors should be reported to CnW Recovery, where we will try and stop them occurring in later versions of the software.