I've happily had a dual boot between Windows 7 and OS X (Hac) set up on my machine for several months. Today I decided to try out Windows 8, having heard good things once you disable Metro by using Start8.

I have OS X on the first hard drive, and it boots by default. To get into Windows 7 I press F12 at the POST beep and then select the second drive.

For the 8 installation, I first physically disconnected the OS X drive (to ensure that the installer didn't overwrite the Chimaera loader required for OS X), then booted from the Windows DVD and proceeded as usual (clean install, not an upgrade). My troubles began after it was all installed and I reconnected the first drive. Windows 8 seems to have hijacked the boot sequence. The system now boots into Windows 8 instead of OS X. Even if I go into the EFI and ensure that my OS X drive is set as the first device in the boot order, it still boots into Windows 8. I can use F12 and manually select the correct drive, which works, but at next reboot it's back into Windows again.

How is this possible? I'm new to EFI but it appears that Windows is somehow overriding my selections, which seems like it shouldn't be possible; I would have thought that my own options would override anything provided by the software vendor.

Can anyone please explain what's going on here? In the meantime I've had to disconnect the Win 8 drive so that it doesn't automatically boot into it.

This looks like an uphill battle because Start8 didn't want to run either, but one thing at a time...