Fix INACCESSIBLE_BOOT_DEVICE with Boot Camp Windows Systems

Like any self-respecting computer geek, I like everything. I typically run-up Windows on my Macs by installing it via Boot Camp, and then booting it as a VM. This lets me run everything in parallel, but also go full native mode when needed.

Recently, I found I couldn’t boot my Windows natively any more, though it would still work fine in my VMware Fusion. When booting natively, my Windows install with BSOD on an INACCESSIBLE_BOOT_DEVICE exception. After a bit of googling, I found that this was likely related to storage drivers. I ultimately managed to fix my Windows environment (without a reinstall), here are the steps:

  1. Launch your Windows environment from within a VM under macOS. You will need to operate on your Windows C:\ from within a Virtualized Environment because the storage volume will be unlocked and accessible, but there won’t be a need for a special driver running under Windows for this.
  2. Use the Boot Camp Assistant to fetch the Boot Camp Drivers. Copy them in to your Windows environment.
  3. Boot the Windows VM from a Windows Installer Disk Image.
  4. Open a command-line by pressing shift+F10 (fn+shift+F10)
  5. Run the command:
    dsim /Image:C:\ /Add-Driver /driver:c:\path\to\your\boot-camp\drivers\$WinPEDriver$ /recurse
    (Update the /driver part to match your system’s configuration)
  6. That’s it, it should have run and now your Windows environment will be natively bootable again, at least, mine is.

This method was adapted from that described here: https://twocanoes.com/knowledge-base/resolving-inaccessible_boot_device-error-after-restoring-winclone-image/