Windows 10 don't want to keep assigned letters for EFI and storage partitions, which is a pain because I need to use diskpart or disk manager every time I want to access one of those.

This is my setup:

  • Disk 0 (as listed in diskpart): 2TB 2.5" SATA SSD with:
    • Partition 1: a useless EFI partition automatically created by macOS when formating the disk for the first time I guess
    • Partition 2: a 931GB partition for macOS storage (my home folder is in there)
    • a 128MB unallocated area
    • Partition 3: a 931GB NTFS partition for shared storage between Windows and macOS. This one is supposed to mount at startup as D:/ (as it did before) on Windows but it wont unless I give it a letter using the disk management utility. It mounts as expected on macOS using Paragon NTFS.
    • another 128MB unallocated area (i dont care but: why?)
  • Disk 1: 500GB M.2 SATA SSD with Windows installation
    • Partition 1: 530MB Windows recovery partition
    • Partition 2: 100MB Windows EFI partition
    • Partition 3: a 16MB partition appearing in diskpart but not diskmanager (we dont mind I guess)
    • Partition 4: 465GB actual Windows partition (C:/)
  • Disk 2: 500GB M.2 NVMe SSD with macOS installation:
    • Partition 1: 200MB EFI partition with OpenCore 0.6.6 on it. I would like it to mount as E:/ on Windows but I need to use diskpart to do so after each reboot (does not work ith disk manager)
    • Partition2: 447GB partition with macOS installation.

My issues:

- I need to re-assign the D: letter using the windows "disk management" utility to my storage partition (disk 0 partition 3) every time I want to access it after a reboot. It was not the case before, I think the problem appeared shorlty after installing Bootcamp utility. It is really annoying as I use this partition almost every time I boot on Windows, and I had no problem with it before installing bootcamp utilities

- I need to re-assign the E: letter using diskpart to the OpenCore EFI partition (disk 2 partition 1) every time I want to access it after a reboot. It is not that much a problem as I need to do so only for debug/maintenance purpose, but it would be awesome to get the letter always assigned.

What I've tried so far:

- reset NVRAM

- "automount enable" in diskpart

- "set id=ebd0a0a2-b9e5-4433-87c0-68b6b72699c7 override" then assigning a letter to the storage partition (disk 0 partition 3) using diskpart, as explained here

- check system integrity with "sfc /scannow" as stated here

- the problem appears whether booting Windows by selecting the Windows disk on the UEFI menu, or through the OpenCore picker.

Any idea?

More details about my setup: i9 9900K, ASRock Phantom Gaming itx/ac Z390 with last UEFI update, RX 590, Windows 10 Pro, macOS Mojave with OpenCore 0.6.6


I had to write this post to find the solution for the first issue:

In Windows command prompt:





as explained here. Now the storage partition properly mount as D:/ after a reboot!

submitted by /u/Blablebluh
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