To change the registry for BF4 you must run regedit and look for(at least in my case): HKEY_LOCAL_MACHINE -> SOFTWARE -> Wow6432Node -> EA Games -> Battlefield 4. Once you've clicked on Battlefield 4 you should look for (on the right side of the screen) GDFBinary, GDFBinary64 and Locale. In my case I had GDFBinary and GDFBinary64 as C:\Program Files (x86)\Origin Games\Battlefield 4\GDFBinary_pt_BR.dll and C:\Program Files (x86)\Origin Games\Battlefield 4\GDFBinary_pt_BR.dll (meaning brazilian portuguese) so I double clicked them and modified the value to en_US instead of pt_BR, also the same thing with Locale. Then, if it doesn't work, go to the folder where you have the .dll files and check if you have the files with the name en_US or the language you want. If you have the files and it is still not working, try taking all the different languages .dll files and leaving only the ones for the language you want. I just moved my pt_BR files to another folder(in case I needed them) and left the en_US files and it worked for me, hope it works for you too. Sorry about the long time it took for me to answer you.