Check to see if your previous version of windows has been removed.
-left click on the start button
-select Settings
-select Storage (from the menu on the left)
-select This PC (from the menu on the right)
-select Temporary Files (on the left. my laptop says that I have 32.5gb of temp files)
-now you can select Previous Version of Windows for deletion (if you're using an Admin account)
My desktop seems to have deleted these files on it's own while my laptop has not