OK, now thanks to JesterDev's manual OS X and Windows 7 now work!
However, there is a minor problem:
Darwin Bootloader automatically boots OS X when the countdown is over - but I want Windows to be the default!
I've already searched a bit and tried
Code:
<key>Kernel Flags</key>
<string>rd=diskXsY</string>
which caused a total crash of OS X.
As an alternative I could also use the Windows Bootloader (actually I would even prefer it), but when I choose OS X in the Windows Bootloader nothing happens - I only get a black screen!
I've also read that Darwin always boots the active partition, however when I set the Windows partition active the Windows bootloader comes up! It also comes up when I select Windows in the Darwin Bootloader.
To sum it up: I either have to repair the Windows Bootloader to boot OS X, or I somehow delete he Windows Bootloader so that Darwin is the only Bootloader and I can set the Windows partition to active and therefore as teh default boot.
Hope you can help me! Any answers appreciated ;-)