ZTE MF 667 Remove Card Lock
DC Unlock is the Most populer application .But its not free. Sonic provide good chance .You can User following URL. http://ineedohelp.blogspot.com/2012/04/internet-dongle-unlock.html Fallow the interaction as it indicates .There is a major difference only on identify device .You need to select ZTE and enable DC Unlock to detect Dongle by clieck on Search. I used this with Windows 10.