Windows.old is huge - what can I delete?

I was doing some disk maintenance checks on my computer and noticed that "Windows.old", the previous OS version prior to upgrading to Windows 10, is a whopping 23Gb in size. It was a bit larger, but I've reduced it a little by removing:
* SoftwareDistribution
* ManifestCache

Are there any other large files I can delete from Windows.old that are non-essential, not required in order to restore the older operating system?

It is just there incase you want to Rollback or find Files that are corrupt so you can get a copy if needed , it usually deletes on its own after 30 days , though I think with AU that is now 10 or 15 days.

If you have a Windows~BT or such folder on C: that is the Download folder from a recent Upgrade it can also be deleted , it is sometime left behind if an Install fails.


KB

After a Windows Upgrade, by default, a scheduled task is created and will run after four weeks to delete the Windows.Old directory. But if you wish, you can also remove the Windows.old folder manually earlier.

Run Disk Cleanup, select Cleanup system files and check remove old Windows installations if you want to remove windows.old now.

After a Windows Upgrade, by default, a scheduled task is created and will run after four weeks to delete the Windows.Old directory. But if you wish, you can also remove the Windows.old folder manually earlier.

I recall that MS promised to do so for my 12040 upgrade. They lied - it never got deleted. I had to do it myself with Disk Clean-up (clean up system files).

I watched out for the AU in case it failed too, but it promptly removed it 10 days (to the minute) after my upgrade. (MS reduced it from 30 days to 10 for the AU.)

I wouldn't go around trying to figure out what to delete in Windows.old as we don't know what is on your computer.
It sounds to me like the 30 day period for windows.old and $Windows.~BT to be automatically removed hasn't been reached yet. On one of my computers it took 35 days for whatever reason, on my other one it took only 31 days. After that I ran disk cleanup to ensure complete cleanup that includes minimizing WinSxs if applicable.
But you could consider what's worth saving in Windows.old if it's possible to do so before it's removed.

Just as an FYI.. here's a very nice tutorial on how to deal with the windows old folder.
Windows.old Folder - Delete in Windows 10 - Windows 10 blog

Just as an FYI.. here's a very nice tutorial on how to deal with the windows old folder.
Windows.old Folder - Delete in Windows 10 - Windows 10 blog

Thanks! Yes, I am relieved to see that it's all temporary... and that Windows should eventually dispense with it. In any case, a proper backup of a good running state suffices for me. I really don't want to go back to Windows 8... even though it was fine in many respects (except for that annoying full screen tile-view).

Thanks! Yes, I am relieved to see that it's all temporary... and that Windows should eventually dispense with it. In any case, a proper backup of a good running state suffices for me. I really don't want to go back to Windows 8... even though it was fine in many respects (except for that annoying full screen tile-view).

@cytherian In addition to the tutorial that BunnyJ posted for you, which was written by one of our Administrators here on windowssh blog, there are hundreds of good tutorials available. Simply go here Windows 10 Tutorial Index - Windows 10 blog or click on Tutorial Index in the menu bar at the top of the page, or type a few keywords in the search box at the top of the page. Just thought it may help in the future. TC

@cytherian In addition to the tutorial that BunnyJ posted for you, which was written by one of our Administrators here on windowssh blog, there are hundreds of good tutorials available. Simply go here Windows 10 Tutorial Index - Windows 10 blog or click on Tutorial Index in the menu bar at the top of the page, or type a few keywords in the search box at the top of the page. Just thought it may help in the future. TC

Thanks, TC. Wow... that tutorial index is HUGE. Brink and others must have spent hundreds of days compiling all that info. This makes anything Microsoft provides online pale in comparison. Btw, given you're multi-booting with 10 and 8, what qualities do you feel 8 has that is missing in 10? If anything?