Error 0x80300024 when installing Windows 7

I have a problem with my MacBook Pro Mid 2012: I used Windows 7 on my HDD and a SSD via USB. Then I went to an Apple Authorised Service Provider and replaced the optical drive with the HDD and the SSD is now there, where the "normal" hard drives are.

No matter what I do, I get error 0x80300024 if I want to install Windows 7 on the HDD, which replaces the optical drive. It works on the SSD, however. I replaced the SSD with another HDD and it works too, so I think that Windows is only bootable on the primary SATA connector, but not on the secondary, where the optical drive was. I tried using the Master Boot Record as well as FAT or just made the hard drive empty. Still the same issue. Windows says that the controller is not activated in the BIOS, but there isn't any BIOS on the Mac, at least no BIOS settings.

Interestingly, it works if I unplug the SSD, so that just my HDD is connected. So I guess Windows has difficulties by recognising two SATA controllers. So I can install Windows 7, but the problem is that "no bootable drive" is found if I connect the SSD again. So Windows is not only uninstallable, it is not bootable too.

Now I would have to options: install Windows 7 on the 120GB SSD, which wouldn't be enough for OS X plus Windows or switch the HDD to the primary SATA connector and the SSD to the other one. This would cost 60 Euros again and I can't believe that there is no other solution.

Did anyone else experiences the same issue or has a solution for me? I just want to install Windows 7 on the HDD and it was working on my old 2009 MacBook Pro, but now it's not working and if I search on Google I just get solutions for the Mac Pro (there it was the RAID, which caused this issue). Others, like Mac mini users, who are using two hard drives, solved this by formatting (FAT32, Master Boot Record and/or just emptying everything and selecting "empty space"). This didn't work for me 😟