Unable to Boot Windows with 'Boot Disk Unavailable' Error After Installing Ubuntu on a Dual Drive System (500GB NVMe, Windows Drive Partitioned)

Dual Drive System Overview

A dual drive system is a computer setup that utilizes two drives for data storage and operating system installation. In our case, we are dealing with a 500GB NVMe drive and a partitioned Windows drive. NVMe (Non-Volatile Memory Express) is a high-performance, host-controlled interface designed for PCIe-based SSDs. The Windows drive in this scenario is already partitioned, preparing it for a dual boot setup, allowing users to choose between Windows and Ubuntu during the boot process.

Installing Ubuntu on Dual Drive System

To install Ubuntu on a dual drive system, you can follow a guide or video that offers detailed instructions. However, sometimes users might encounter issues after the installation process, such as being unable to boot Windows. Continue reading for suggestions on how to resolve this issue.

Unable to Boot Windows: Common Reasons

After installing Ubuntu on a dual drive system, if the computer fails to boot into Windows, it may be due to the following reasons:

• The boot order is configured incorrectly, with the Ubuntu boot loader prioritized over the Windows boot loader.
• The Windows boot loader was overwritten or removed during the installation of Ubuntu.
• The system's EFI/UEFI settings may have been changed.

Resolving Windows Boot Issues

To resolve the boot issue, you can try the following steps:

Step 1: Boot into the Ubuntu Live Environment

Boot your computer with the Ubuntu installation media and select "Try Ubuntu" from the boot menu.

Step 2: Access UEFI Settings

Restart your computer and press the key to enter the UEFI settings (normally F2, F10, F12, or ESC). Refer to your manufacturer's documentation if needed.

Step 3: Adjust Boot Order

In the UEFI settings, ensure that the Windows boot manager is listed before the Ubuntu boot loader in the boot order.

Step 4: Access Windows Recovery Environment

Restart your computer and boot into the Windows Recovery Environment. See Microsoft Support for guidance.

Step 5: Reset Windows Boot Loader

< !-- language: lang-bash -->
bootrec.exe /fixmbr
bootrec.exe /fixboot
bootrec.exe /rebuildbcd

Run these commands in the Windows Recovery Environment to reset the Windows boot loader. See Microsoft Support for the full instructions.

Step 6: Update GRUB Boot Loader

After resetting the Windows boot loader, boot back into Ubuntu and update the GRUB boot loader to recognize Windows again.

< !-- language: lang-bash -->
sudo update-grub

Installing Ubuntu on a dual drive system can be seamless with the right guidance. However, boot issues may arise due to incorrect boot order, overwritten boot loaders, or modified EFI/UEFI settings. By following the steps outlined above, you can resolve the Windows boot issues encountered after installing Ubuntu on your dual drive system.

References

• Microsoft Support - Start your PC in the Windows Recovery Environment
• Microsoft Support - Use Bootrec.exe in Windows