Windows still shows as used the space I freed of older Windows.

Hello, I deleted my older Windows 10 partition.
It was on another hard disk, different from what I use now as my main drive and partition.
To do that, and avoid all access denied and permissions messages, I copied all Windows folder in a new created folder called windows.old, and I used the windows tool to delete Old Windows installation on that drive. I saw this trick in a video on YT.

It worked. Now the Windows folder is disappeared, and also WinDirStat and TreeSize, shows as used space on that drive only 18 Gb.
Problem is: that "This PC" menu of Windows, still shows 28 Gb as used space on that drive. Why?
Obviously, I have "show hidden files" enabled, and there is nothing hidden. I used Administrator mode for Windirstat and treesize, etc..
I can't figure it out.

Seems that these 10 Gb are used from some process, but that drive is not my active main drive now.

You empted the bin?

Yep. These are TreeSize and Drive properties. Available space seem to be the same, but used space isn't.

Something you could try if you cant see anything in Windows.
If you can get into your BIOS, go to the section or tab to update the BIOS or flash BIOS. There should be a directory there to choose from. You might be able to see this other drive from here and if so, some type of Junction file might show up.

Siegfriedm said:

Hello, I deleted my older Windows 10 partition.
It was on another hard disk, different from what I use now as my main drive and partition.
To do that, and avoid all access denied and permissions messages, I copied all Windows folder in a new created folder called windows.old, and I used the windows tool to delete Old Windows installation on that drive. I saw this trick in a video on YT.

It worked. Now the Windows folder is disappeared, and also WinDirStat and TreeSize, shows as used space on that drive only 18 Gb.
Problem is: that "This PC" menu of Windows, still shows 28 Gb as used space on that drive. Why?
Obviously, I have "show hidden files" enabled, and there is nothing hidden. I used Administrator mode for Windirstat and treesize, etc..
I can't figure it out.

Seems that these 10 Gb are used from some process, but that drive is not my active main drive now.

It could be system files (perhaps paging file?) that are hidden, this is different from the "Show hidden files" option and can be enabled from the same menu.