I'm using grub4dos and installed Win10 on a separate partion on my SSD.
However now whenever I boot either Win8.1 or Win10, it gets stuck on the boot screen for about 60s before the animation circle appears and then it loads normally.
I think the boot screen I'm seeing, regardless of which Windows I boot, is the Win10 (four blue segments) one as it seems different to what I remember, although to be honest I couldn't describe what the Win8.1 screen looks like so I could be wrong.
I checked with EasyBCD from Win8.1 and found that the System Store it was loading was the Win10 one but that was just because the Win10 partition was active. It doesn't seem to actually affect the boot process and that must have been using the correct BCD or else I don't think WIn8.1 would load at all but I've edited my menu.lst now to makeactive the correct partition like so: