Whenever you upgrade your Windows operating system from old to a new version, install Windows without formatting the drive, or when you refresh your Windows, the “Windows.old” folder appears in the root directory.
If you install a fresh Windows operating system by removing any older version of Windows, you will not see or notice any such folder in your root directory.
The “Windows.old” folder keeps all files and applications from the previously installed Windows. Windows installer uses this folder when you want to revert to the previous version of Windows, or when the new Windows installation fails to complete.
It is safe to delete the “Windows.old” folder if you have no plans to revert to the previous version of Windows.
The “Windows.old” folder carries all Windows operating system files and applications so it can occupy a significant amount of disk space that may be up to 10 to 15 GB. The size of this folder depends on the total size of the previous Windows installation.
Users with the space constraints such as someone who installed Windows on a smaller SSD drive or users who allocated relatively smaller drive space to the windows installation drive might want to remove this folder to free up some valuable disk space.
Deleting Windows.old folder is not as simple as deleting any other file or folder still not very complicated. In this article, we will show you how you can delete the Windows.old folder by using the disk cleanup utility that is available in Windows.
NOTE: Do not delete this folder if you plan to downgrade to the previous version of Windows. If you have no plans to revert to the older version of Windows, you can go ahead and delete the Windows.old folder without any hesitation.
Remove the “Windows.old” Folder Safely in Windows 10
Double click “This PC” and right-click on the Windows installation drive (Normally the C: Drive) and click Properties.
Under the General tab, click the Disk Cleanup button to start the Disk Cleanup Utility.
The Disk Cleanup utility will make a few scans, on the next dialog box, click the “Clean up system files” button.
The utility will start scanning the system files
As soon as the scanning is complete, a dialog will appear, look for the Previous Windows installation(s), or Windows.old folder entry. Check this entry and click the OK button to delete the Windows.old folder.
The Windows.old folder should no longer appear in the Windows installation directory.