An operating system wasn't found, try disconnecting any devices that don't contain an operating system

Question

I am currently working on installing Windows Server 2022 on HyperV that installed propely but when restarting the VM, I got the following error message:

"An operating system wasn't found. Try disconnecting any devices that don't contain an operating system."

Here’s some context about the situation:

1. My computer was working fine until this issue suddenly appeared.
2. I have not made any major hardware changes recently, except plugging in a USB device once before this happened.
3. The error persists even after restarting the system multiple times.

However, the problem remains unresolved. Can anyone guide me on how to fix this issue? Is it possible the bootloader is corrupted? Detailed steps would be appreciated!

Answer 1

Error: An Operating System Wasn't Found – How to Fix?

The error message "An operating system wasn't found, try disconnecting any devices that don't contain an operating system" occurs in Hyper-V when a virtual machine (VM) cannot find a bootable operating system.
This issue typically arises due to

• Misconfiguration in the VM's settings
• Or missing bootable media.

In my case, I faced this issue before, and it was solved in the following way:

1. From the "Actions" menu, click CTRL+ALT+DEL, then press any key to boot from the OS ISO image.
2. The Windows installation should start. Click "Next," then select "Repair Your Computer" > "Troubleshoot" > "Command Prompt."

3. Type the following Command to recreate the Boot files.

    bcdboot C:\Windows /S C:
   

4. Then run the below Cmdlets, one by one to set the Drive C as an active drive

    diskpart
    list vol
    sel vol C
    active
    exit
   

5. Then restart the computer.

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