Re-format to exFAT splits partitions (4TB) (EDIT)

Hello all,

I just purchased a 4TB WD My Book External Drive and, after using another one which I never re-formatted, wanted to re-format to exFAT so it was compatible with both my Windows and my Mac.

I tried to follow the instructions step-by-step as WD provided in their support pages (using the Windows 10 sequence), but I was not allowed to enter a partition that was larger than ~2TB. One step noted that I could add an extra partition to fill more space, and my disk management says that I have unallocated space, but when I try to click “New Simple Volume,” I can’t access it, it is faded gray.

If anyone knows why I might be having this problem or if there is an alternate solution to get back my original space, I would greatly appreciate it. I’d like to know I didn’t pay full price for half the space because I couldn’t format it correctly.



So, I managed to rectify the amount of space I had using the WD Quick Formatter. However, I’d still like to make my disk exFAT to be compatible with both a Windows and a Mac. How can I properly do this if the method WD Support provides will not work for me?


Hi, if you have a Mac you should be able to format the 4 TB in exFAT, if you are unable to do it, you might need to use a third party app to do it.