After upgrading Windows, old Windows data is saved under Windows.old folder. After upgrading without keeping files, and if you notice you forgot to backup some files, you might be able to pick up files from here, or, you might use to restore back to old version of Windows. Once you are comfortable with your new Windows version, and no longer need old Windows files, this just trashes your HDD space, especially for Laptops with less storage area, like SSD. This old data may take more than 20 to 30 GBytes of space.
You can check if you have Windows.old folder, and size of folder, by opening file explorer and go to root folder in system drive (normally C:). Look for Windows.old and right-click then property for size.
To delete this folder, you can’t simply drag to Recycle bin or by delete command. However, steps to delete is easy.
In file explorer, right click C: drive (or whatever your system drive is), open property, and click “Disk Cleanup”. Or, from All Apps, launch “Disk Cleanup”. To launch from All Apps, you have to check “yes” for “Show administrative tools” in Tiles option (Start Screen, setting charm, then Tiles).
From disk cleanup, you can delete files from recycle bin, temporary files, and other unused files. Old Windows files are not initially listed, so click “Clean up system files”.
“Previous windows installation” and “Temporary Windows Installation files” will be listed, so check them and click OK.
It will ask for confirmation, so click Delete Files.
This will remove Windows.old folder and files used during installation, giving you more free disk area.
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