Folks, probably a Friday topic, but FYI ... I was doing some Sunday evening backups and cleanups and I noticed a Windows.old folder taking about 20GB with ~120000 files in it! Now the weird thing is that I have no clear idea when or where this came from. I didn't run or accept any major upgrades, and my Win10 C: drive was installed fresh a few weeks ago.
You may recall two Monday mornings ago I booted and received a weird (and scary) windows update style message about "your files are still where you left them" and all my customisations had been reversed. Someone in here suggested that I had been upgraded to Windows 10.1, which is possible, but I find no record in the update history. I can only guess that I did receive a gigantic OS upgrade without warning, creating the Windows.old folder. This does worry me, as I like to have control over major decisions like this, and I certainly did in older versions of Windows. Even iOS is more polite and helpful about performing vast upgrades. You have to login as local Administrator, take ownership of the folder and propagate full control all the way down before you can delete it. *GK*