Info and artwork movies

I currently use a raspberry pi b + with kodion my TV as a media center. The kodi is installed via Openelec
I also overclocked the raspberry to 1ghz and there is a fan sitting on top. The films the raspberry must play comes from a nas (freenas on a old PC).
Now I last kodi installed on windows to see what it looked like there and it turned out that the version on windows downloads artwork and info from the movie automatically I dont get this on the kodi that is working on the raspberry. I have all addons that were active in Windows also downloaded to the kodi in OpenELEC. Should I turn on additional addons somewhere or how does this works? The windows version had the kodi version 17 and the kodi on OpenELEC version 16.