We often have multiple Windows installed on a same computer, but most of them are no longer in used. Each Windows folder occupies around 20 GB or so hard drive’s space. Removing these old Windows folders will save you a significant amount of disk space. However, the Windows folder cannot be deleted simply by pressing Del or Shift-Del. The deletion will fail and you will get an “Access Denied” or “Permission needed” error that cannot be bypassed.
Thus, this guide will show you how to correctly and permanently remove old Windows folder that you no longer need in Windows 11 or Windows 10.
Also see: How to Force Delete a File in Use by Another Program on Windows 11/10
How to Delete Old Windows Folder in Windows 11/10
Delete Windows.old using Disk Cleanup
The easiest and the first method you should try before going for the harder ways is to use the Disk Cleanup tool in Windows 10/11. Here’s how.
On the drive where the Windows folder that you want to delete resides, right-click on the folder and rename it to Windows.old. This step is important as it is required for Disk Cleanup tool to detect there is an old Windows folder that can be removed.
After renaming the folder, go to start menu or Cortana, search for Disk Cleanup tool. Right-click it and then select Run as administrator.
Select the drive where your Windows.old folder is located, then click OK.
Under Files to delete section, select the option for Previous Windows Installation(s). Then, click OK to begin the cleanup. It may take a couple of minutes to complete the removal. After the process is completed, the Windows folder should be gone.
Related: How to Delete System 32 in Windows 11
Delete Windows.old using Storage in Settings app
If the Disk Cleanup tool in Windows doesn’t work to remove the Windows.old folder (stuck or crashes during calculating or cleaning process), you can instead use the Storage sense in the Windows 11/10 Settings app to remove the folder. Similar to the method above, you will have to first rename the Windows folder that you want to remove to Windows.old.
Then, head over to the start menu and search for Storage. Select Storage (system settings) from the search result.
In the right panel, select the drive where the Windows.old folder is located.
Within the list of storage usage, select Temporary files.
Scroll down to look for an option called “Previous Windows Installation(s)“. Select it and, alternatively, you can select other temporary files that you may want to remove together. Then, scroll back up and click on the Remove files button. Upon completion of the removal process, the Windows.old folder should be deleted.
Read: How to Delete a Ghost File or Folder in Windows 11/10
Delete old Windows folder manually with CMD
If both methods above fail to remove the Windows.old folder from your drive, or that the Previous Windows Installation option doesn’t show up in Disk Cleanup tool in Windows 11/10, here’s a manual way to remove the folder by using a series of commands in Command Prompt.
To do this, go to start menu and search for CMD. Right-click Command Prompt and then select Run as administrator. Enter the commands below each line at a time. NOTE: Replace C:\Windows.old with the actual path to the Windows.old folder you want to remove, if it’s not in C: drive.
takeown /F "C:\Windows.old" /A /R /D Y icacls "C:\Windows.old" /T /grant administrators:F rmdir /s /q "C:\Windows.old"
The first and second lines of commands may take some time to run. The first command is to take ownership of the entire Windows.old folder file by file, whereas the second is to give full control permissions to the Administrator group. The third line is to remove the folder entirely after successfully getting the permission.