Old Windows 10 Files

I have a few computers, all of which are running various builds of Windows 10 Pro. One of them, running 1709-16299.431, has three old version files; Windows.old, Windows.old.000 and Windows.old.001. All of these are more than four months old, negating the notion that they will go away by themselves given time. Can someone give me a straight answer as to how I delete, or otherwise lose, these files? It’s a tight drive and frankly, I need the space. I’ve tried every published suggestion to no avail.
Thanks.

JLOB

I used the Disk Cleanup tool (Clean up system files). It cleaned up the old installation files but left a zero byte file that cannot be found when attempting to delete the folder. It is C:\Windows.old\Users\(my user name)\AppData\Local\Packages\Microsoft.Windows.Cortana_cw5n1h2txyewy. Any advise?

Deleting after booting into a command prompt did not work. The same file not be found error resulted.

However, I tried Option 2 of the "Windows 10: Delete Windows.old Folder in Windows 10 " tutorial and in an elevated command window I ran the following commands. The file was removed after the last step even though step 2 failed.

takeown /F "C:\Windows.old" /A /R /D (THIS STEP WAS SUCCESSFUL, NO ERROR)
icacls "C:\Windows.old" /grant *S-1-5-32-544:F /T /C /Q (THIS STEP FAILED WITH A FILE NOT FOUND ERROR)
RD /S /Q "C:\Windows.old" (THIS STEP WAS SUCCESSFUL, NO ERROR)

(Problem solved for my situation.)

Cleaner never gave me the "Clean old Windows files" option, so THAT didn't work. Option two, via the elevated command prompt DID clear the "windows.old" directory, but did nothing for the "Windows.old.000" or the "Windows.old.001" files. I DID solve my problem through a 'brute force' method - I backed up my drive using, Acronis True Image, but excluded the problem directories. I took the resulting backup and reloaded the problem drive. It worked well, but threre's GOTTA be another way!
Thanks for all the advice.
JLOB