Okay so I have something really weird. I’ve never encountered this before either.
So I just got done formatting an external USB drive in Yosemite as GUID, partition 1: Mac OS Extended Journaled, partition 2: NTFS, partition 3: Ext4.
The NTFS partition works fine in Windows 10, but is NOT recognized or functional in Windows 8.1.
Anyone got any ideas?
can Windows 8.1 see the partition table? if so, it could be that dumb “fast boot” thing Windows 10 does, which renders NTFS partitions unmountable on any other system.
if Windows 8.1 cannot see the table, then it might be some odd table format. in this case, convert it to GPT, as GPT is basically the universal table format.
It’s really weird because it works fine with internal drives, such as the multi-booted drive you’re booted into from, but not external ones such as a USB. It’s the same thing, one of them is just internal, and the other is external.