Hi @ all,

So I downloaded the game the whole night, and now I can't install it cause the installer says that part 4 is corrupted.
I downloaded this part now 3 times in a row, and everytime the same problem occours.

What I've tried: Running the Installer as admin, rename all bin files to bin files (if there would be rar files but nah ^^)

So now I see: Downloaded the setup again and now the check tells me: Setup is corrupted...does ist matter that I download ALL Files in German or English?

1. The installer is in English, for German you need to download the language pack.
2. It' is what it said, 4.bin is corrupted, you really need to re-download it. You can check all files' hash sums against those in this nice FAQ. If they're all ok, try installing again.
3. If direct downloading fails every time for you, it's time to try GOG Downloader as a more reliable means.
4. As a last resort I'd recommend using Galaxy to download the game itself (not the installer). But you can try download the installer as well. Just remember Galaxy will re-write all the data you're going to download (extras and installers, not the game).

EDIT: Apparently I was wrong in point 1, you do have installers and patches in different languages at least for GOG Downloader links. Make sure you downloaded the same language for both.