Ubuntu – Windows 10: Inaccessible Boot Device after dual boot Ubuntu 18.04 Installation

bootdelldual-bootgrub2windows 10

I just got a Dell Inspiron 7580 with Windows 10 pre-installed. I wanted to install Ubuntu so I followed the usual instructions:

  • Disabled Secure Boot
  • Disabled Fast Startup

I tried to install from a USB stick but the installer could see no disks at all. I then switched from RAID to AHCI. The installation was completed successfully and everything seemed to work fine.

After the installation I wanted to check the pre-existing Windows 10 installation and selected Windows Boot Manager, only to see the infamous INACCESSIBLE_BOOT_DEVICE screen.

Everything is OK in the Ubuntu installation.

A pre-installed recovery tool from Dell reinstalled Windows 10 but still the INACCESSIBLE_BOOT_DEVICE message appears.

Best Answer

  • My problem was apparently different from the suggested question.

    The issue I had was that in AHCI mode, Ubuntu booted and worked normally but Windows did not boot at all. Then I switched to RAID and noticed that Windows booted and worked normally but Ubuntu did not boot at all.

    The problem was that I had switched from RAID to AHCI without safe mode in Windows. When I applied the same switch but in safe mode everything worked fine.