Cant delete windows old folder

I tried all in this thread to delete or move C:\Windows.old including adding take ownership of to my context, AOMEI Backup - which made a backup to another drive at least minus the ones in use but did not keep a log so I could review these files in use, file assassin, ADK, logged on as Admin, and some others. I cant find Previous Windows Versions Installations either which was mentioned.

I was able to change ownership to Admin, but system also has full permissions and when logged in as admin it says I need system permission, I could delete all inheritance from system, but got scared off. I was able to delete a few individual files, but not all, and going through 12,000 files one x one is not a fun proposition.

My Windows.old file is 21GB, and it never gets deleted despite what MS Help pages report Just had Fall update today and it increased again. My C: is only 55GB and this is 21GB of it while I have TB's worth of external storage connected on my personal, where I apparently am not the owner, if I were, I could delete this and would have days ago, but still cannot.

The reason being is that I have over 150 files that are in use from Windows.old when starting in safe mode. That is crazy. Some from a printer I no longer own. And if they auto start in safe mode, how can I kill them as they will always be running.

I'm assuming the boot from a live Linux is for Linux only.

Per f14Tomcat / SteveC's comment about using Autoruns from systeminternals. I d/l it and ran and saved a copy of its findings. Quite detailed and color coordinated. I picked one, then a second random file. The file was from an old printer I no longer have which I can find in explorer, but not delete as it is apparently in use, then tried file assassin and it was unable to even locate the file at all.

pretty stuck, once again

Barman58:
I followed your advice, although I had already ran disc cleanup, this time I just went for it in extended cleanup, hit all but user file history and windows esd install files. Only because they seemed they might come in handy, but that was just a shot in the dark.
windows.old is not showing up in C: where it had previously. Freed up 10GB on C:
The odd part is that windows.old was 21GB, what happened to the other 11GB.
I also had backedup windows.old, at least all that I could, by utilizing the suggestion of AOMEI Backup to an external drive, just in case.
I still need to dig around a bit as I was not expecting to remove files from any other than C:, not sure if I missed a step but had never ran the extended cleanup, that trick alone was worth the price of admission.

Well Barman, from one 58 to another, a tip of me hat to ya, Kudos, a double sawbuck in yer jar, and Now BARMAN58 at the bar is a friend of mine, He gets me my drinks for free, And he's quick with a joke or to light up your smoke, But there's someplace that he'd rather be. He says, "lambert58, I believe this is killing me." As a smile ran away from his face, "Well, I'm sure that I could be a movie star,If I could get out of this place."
AND I am just a monkey man and I'm glad you are a Monkey too man!

It was of GREAT assistance, and KUDOS to Barman58 and Kari.
I really Liked Grape Ape, and wowza wasn't Mata Hairi a hot number...........