This might solve some users multi- boot problems

Apr 1, 2012
MSI MPG Z490 Gaming Plus
i7 10700
RX 580
  1. MacBook Pro
  2. Mac mini
Mobile Phone
  1. Android
  2. iOS
I do not know why this worked but it may help others.
I had a stable multi-boot machine with Mountain Lion and Windows 7 sharing an SSD and Win 8 on a second SSD. A Win 8 update trashed the Win 8 install (who would have thought?) and lacking a recent image of the drive (my bad) I had to reinstall Windows 8.
That trashed the Chameleon boot loader.
Using the Unibeast USB key I booted into Mountain Lion and reran Mulitbeast. That did not restore the Chameleon boot loader, which it has in the past under similar circumstances.
I already had BCD 2.1 installed on the Win 7 partition. Using BCD I added the Mac OS with the MBR option.
Choosing the Mac OS at boot-up would get to the Chameleon splash screen/timer but the system would hang.
After researching I followed the instructions using Unibeast to boot to the installation screen and make sure the Mountain Lion partition was active/bootable (
Now the system boots to the Windows boot screen with options for Win 8, Win 7 and Mountain Lion and, at least for the last several days, all boot stably. The Mountain Lion option boots to the Chameleon splash screen/timer and then ML boots.
Using BCD under Windows does not reliably work to boot to a Mac OS. But if the extra step is taken to ensure the Mac Partition is active and bootable perhaps it will work for others. Obviously the Chameleon bootloader has to also be installed on the Mac partition.
Who knows what Windows 8.1 will do . . .