Ok i think i found a way to change the language (voices and text) using regedit
1- First of all you MUST have the game with the language you want to change it, if the game only have English or you dont know what languages you have in the game files, update it with Battle.net, then you can uninstall Battle.net
2- copy/paste the code below in to a text editor (notepad for example) and save it with the extension ".reg" let say... "language_changer.reg"
[HKEY_CURRENT_USER\SOFTWARE\Blizzard Entertainment\Battle.net\Launch Options\OSI]
"LOCALE"="xxXX"
"LOCALE_AUDIO"="yyYY