It was not possible to make Win 7 use the nVidia driver:
- the setup program of nVidia didn’t install the drivers because it didn’t find an appropriate device
- I forced a driver installation via the Windows device settings
But during reboot with the nVidia graphic card I always got the BSOD STOP 0x124 0x4 all over again.
So I lost the battle and gave up – and ghosted Win XP back …