

Although the hybrid MBR should work OK with your Windows system, it's conceivable that it won't, or it might be interacting badly with a removable disk, so you might want to avoid it. For the rest of my answer, I'll assume you're talking about a removable disk that you're moving between two computers.Īnother potential issue is that OS X partitioning software (at least, as of a year or two ago I haven't checked recently) creates a hybrid MBR if you put a FAT or exFAT filesystem on a partition. If so, at least part of the solution would be to put the Windows partition first on the disk.

This is definitely how Windows treats USB flash drives, but I'm not sure if it treats removable hard disks in the same way. Is this an external disk that you're moving between a Mac and a Windows PC? If so, it's conceivable that Windows is refusing to access anything beyond the first partition on the disk.
