MacBook booting with wrong keyboard layout
Things you could try:


Run sudo rm ~/Library/Preferences/com.apple.HIToolbox.plist ~/Library/Preferences/ByHost/com.apple.HIToolbox.*.plist /Library/Preferences/com.apple.HIToolbox.plist and restart. The current keyboard layout is stored in the first file in 10.9 and the second file in 10.8. The keyboard layout used in the login window and by the guest account is stored in the third file.
Run open -a KeyboardSetupAssistant to identify the keyboard.
Run sudo rm /var/db/.AppleSetupDone;sudo /System/Library/CoreServices/Setup\ Assistant.app/Contents/MacOS/Setup\ Assistant and create a new account. Set the default keyboard layout to Swiss German in the second step and enter anything else in the other steps. You can delete the account after you have created it.