After following the steps below, any information or data related to Windows 8 will be deleted
When Disk Management is displayed, we need to delete the corresponding partition of Windows 8. Right-click the partition on the drive and select Delete Volume , click Yes at the next screen:
And that partition will be deleted and displayed in black as shown below:
Next, right-click the partition just above (blue) and select Extend Volume:
From this step, keep the default options and click Next> Next> Finish to finish the process. Once completed, the partitions on the computer will revert back to before you installed Windows 8.
In this case, all you need to do is delete the VHD file on the root partition (drive C):
Very simple and easy. Good luck!