Windows 10 System files, missing disk space

Question

I have performed an upgrade from Win7 to 10 recently and seem to be missing a lot of disk space. I've done through the usual cleaning processes but I seem to have a lot taken up by "system files", 190GB to be exact.

Is this normal?

Answer 1

Yes, it is normal.

During the upgrade, the previous Windows folder is renamed to Windows.old. This is for the purpose of reverting back if the upgrade fails. If you check the size of this folder, it will likely be the size of the missing space you are referring to.

source (even though it is for Windows 8, it applies)
source

Answer 2

Yes. This is normal behavior.

This folder is created when you upgrade from one version of Windows to another, starting with Windows Vista. The Windows.old folder actually contains all the files and data from your previous Windows installation. It can be used to restore your system to the old version of Windows if you don’t like the new version. If you’re looking for a specific file that wasn’t properly copied to your new Windows installation, you could also dig into the Windows.old folder and find it.

See this link how to delete the folder:

http://answers.microsoft.com/en-us/insider/forum/insider_wintp-insider_files/windowsold-folder/1c356ddb-4a15-4165-b1c0-2d1b1e93b0b5

Answer 3

The space missing from your disk drive, these files are used by your PC to revert back to older OS. If you are loving Windows 10 and don’t plan to get back to the older operating system, you can tick this option and move ahead, use Disk Cleanup program to free up this space.

I suspect that after the 30 day period this folder will be removed automatically. One thing is for sure – there is only a 30 day window to revert back to your previous OS. After you done it, you won’t be able to restore the former version of Windows.