language files

hi,
I installes WordPress locally, so I can’t update automatically. (I’m not prepared to use my pc as server).
Now I get the information that updates for language files are available – I looked in the documentation and your meant to be able to download a .mo file, but there is no .mo file.
Wordpress itself is in German.
Is there an easy way to solve this minor irritation or must I remove one plugin and theme after the other until the warning goes away?
If so – where do I then get the translation file from.
already with thanks and please excuse my english
martin