Here's something I've wondered about for years and never got around to asking. A recent example:

I reinstalled Win 10. I transfered all data from Windows old to the new OS. When I highlight the Windows Old folder, it says it is empty. but when I start to delete the folder, the progression bar shows several hundred files being deleted. If the folder is empty, where do these figures come from?

Thanks

The Windows.old folder is normal. There are a lot of articles about it on the web so I will avoid duplicating the web here. After some time, Microsoft will clean it off for you. You can ignore it if you wish or you can do more research.