How to resolve the error 'Unable to start the Hyper-V Virtual Machine'

How to resolve the error 'Unable to start the Hyper-V Virtual Machine'

Introduction

When attempting to power on a restored VM in Microsoft Hyper-V, you may encounter the error "Unable to start the Hyper-V virtual machine" during the last steps of the restore. This issue can arise due to various system, configuration, or resource-related problems. This article outlines common root causes and steps to resolve them.

Resolution

Below are several potential causes of this issue and instructions to resolve each:

Insufficient System Resources

Cause: The host machine does not have enough available RAM, CPU, or disk I/O to start the VM.

Resolution:
  1. Close other applications or shut down other running VMs to free up resources.
  2. Reduce the allocated memory or number of virtual processors for the affected VM.
  3. Check available memory in Task Manager or Resource Monitor.
  4. Reboot the Hyper-V host.

Incorrect VM Configuration Settings

Cause: The VM may be misconfigured (e.g., invalid virtual switch, disk path, or assigned resources).

Resolution:
  1. Open Hyper-V Manager, right-click the VM, and select Settings.
  2. Verify that the virtual hard disk (VHD/VHDX) file path is valid and accessible.
  3. Ensure the assigned virtual switch exists and is correctly configured.
  4. Adjust memory (RAM) and processor (CPU) settings to match available host resources.

Hyper-V Services Not Running

Cause: Required Hyper-V services may not be running on the host.

Resolution:
  1. Press Win + R, type services.msc, and check the following services:
    1. Hyper-V Virtual Machine Management (vmms).
    2. Hyper-V Host Compute Service.
  2. If stopped, right-click the service and select Start.
  3. Reboot the host if services fail to start manually.