Download this driver for P6350. http://support.lexmark.com/index?page=content&actp=DD_LIST&productCode=LEXMARK_P6350&id=DR8593&os=WINDOWS_VISTA&oslocale=en_US&segment=DOWNLOAD&userlocale=EN_US&locale=en
Not sure y U get this error. Reinstalling the latest driver always helps as Win 7 simply loves working wt new driver ha ha.. Lexmark itself has recommended using Vista drive for Win 7. May b tey're still in the process of releasing driver fo Win 7. Never mind.. Just download the driver n njoy!