Can't delete windows.old folder  

It should be run as administrator.

lopedoggie said:

If you delete it you can't go back to last known good configuration before the update. If you are satisfied that your system is stable after the Anniversary Update and need the drive space I would delete the contents. I believe the actual folder stays put and maybe some artifacts will remain in it that just refuse to delete (my system has two windows old folders with some do nothing files). Do not follow my advice on this unless you are dead sure positive that your system is rock solid stable. Maybe wait a week or two.

The proper procedure is here: https://www.tenforums.com/tutorials/2...dows-10-a.html

Hi there

the BEST way of reverting to a previous version of Windows is the following:

1) BEFORE upgrade image your Windows partition - don't forget the system reserved one as well --something like Free Macrium works fine.

2) After upgrade if you want to revert simply restore your backup image --incidentally before reverting take another backup of your updated windows as you might want to use it again without the re-install / upgrade process having to be re-run.

Normally the windows.old file can be deleted in the Disk cleanup --can't say it asked to be run as admin.

Another foolproof method is to boot say a Linux Mint system from a USB stick and use the file manager to delete the windows file. File manager in Linux is usually called something like Dolphin, Nautilus, Midnight commander etc --it's pretty obvious which one. Linux Mint is reasonably like Windows for doing this type of stuff.

I'm running a Linux VM - same principle applies




Cheers
jimbo

An easy way to delete the residual files left in windows.old is to boot from a linux drive or a winpe drive (eg a Macrium Reflect recovery drive).