If you update your launcher and change the language you may receive the error stating that MSVCP120.dll is missing from your computer.
In order to fix this problem you need to download http://www.microsoft.com/en-us/download/details.aspx?id=40784 which should fix up your problem in no time.
Make sure however that you get the x86 even if you are running an x64 OS. This is important as the x64 version isn't compatible with some 32 bit applications, DBOG being in that group. This will fix your problem completely.
Just to save everyone panicking or worrying!
If there are any other problems with the launcher language change you can post in here and I will try to find an answer for you.