After upgrading to Windows 10 now remove the previous Windows 8.1 installation

Follow these steps to remove the Windows 8.1 installation after upgrading to Windows 10.

Open the start menu and start the Disk Clean-up program:

Select your Boot OS Drive:

Tick the Clean up system files button:

Again select your Boot OS :

Notice the Previous Windows installation option.

Ofcourse… select it to remove your previous installation.