Forum Discussion
Is it safe to delete the previous Windows 10 installation files?
During a disk cleanup, the tool detected old Windows installation files that are taking up a significant amount of space, and I’d like to delete them to free up disk space. I’d like to confirm whether deleting them will affect the normal operation of the current system or any future rollback operations.
2 Replies
The safest and most reliable way to delete these files is to use Windows' built-in tools, which are designed to handle the special permissions of the Windows.old folder. Deleting it manually via File Explorer often fails or causes errors.
The 657 GB item shown is the previous Windows installation in Windows.old. You can remove it without disrupting the current installation if Windows is working correctly, but the choice is permanent: Windows will no longer be able to use “Go back” to restore the earlier version. Before deleting it, open Settings > Update & Security > Recovery and decide whether you still need the Go back option. Also check Windows.old for any personal files that were not carried into the current installation and copy anything needed to another drive. Then reopen Disk Cleanup as administrator, choose Clean up system files, select Previous Windows installation(s), and confirm Delete Files. Keep the PC powered on until cleanup finishes. If the current installation has driver, application, or stability problems, do not delete it yet. After deletion, returning to the earlier version would require installation media and a reinstall rather than the built-in rollback.
