qdv.dll errors are system errors that do not allow the users to open certain applications or files installed on the system. There can be many reasons behind the appearance of errors related to qdv.dll files such as old drivers, virus infections, registry issues etc. In order to make a resolution to the error, you can use driver updater software that updates the obsolete drivers. But if the problem is due to registry problems, then you must use Registry repair software that is highly capable to remove all the corrupt or invalid entries available in the Registry editor and hence fixes up the qdv.dll errors. For more info http://www.qdvdllerrorfix.com