hi i am new in dahua dvr,i buy an Dahua 8 channel dvr,i install correctly and use for few days only, after that when i check the record the language is change, so i go to system and try to change the language to English but it is not possible to change it. when i click to the language box there is no option appear in the language box.i tried to reset in factory settings but same problem.any body can help me for this problem? thank you and god bless you all.