When you upgrade to a new version of Windows 10, it keeps the old installation files intact. This helps you downgrade if you don't like the new version or if you are facing problems with the new upgrade. Typically, these old Windows installation files will be anywhere from 10GB to 30GB. As you can guess, that is a lot of hard disk space to spare. So, if you are sure you are not going to downgrade, deleting these old Windows installation files can free up some essential space.
Follow the below steps to delete previous Windows Installation files.
Steps to Delete Previous Windows Installations
There are two ways to delete old Windows installation files. The first method is to use the Storage Sense feature in Windows 10 via the PC Settings app. This is the easiest and quick way to delete previous Windows installations. The second method is to use the good old Disk Cleanup tool. Both methods achieve the goal we set. Follow the one you are comfortable.
Warning: Once you delete the old Windows installation files, you will not be able to downgrade to the previous version of Windows.
PC Settings Options to Remove Old Windows Installation Files
There is a new feature called Storage Sense in Windows 10. This feature allows you to remove the old Windows installation and other temporary files. Compared to the old tools, Storage Sense is much more easy to use and you can even configure it to delete temporary files automatically. Simply put, Microsoft made a brand new tool to free up space in Windows 10.
1. Of course, the new Storage Sense feature is located in the PC Settings app. So, press the Win + I keyboard shortcut to open the PC Settings app.
2. In the PC Settings app, go to System -> Storage page. On the right panel click on the Configure Storage Sense or Run it Now link appearing right under Storage.
3. Here, under the "Free up space now" section, select the Delete previous version of Windows checkbox and click on the Clean now button.
As soon as you click on the button, Storage Sense will delete previous Windows installations. As a result, you will get back anywhere from 10GB to 30GB free space.
(Alternative) Disk Cleanup Tool
As an alternative, you can also use the Disk Cleanup Tool to remove old Windows installation files. The good thing about Disk Cleanup Tool is that it works in Windows 7 and 8 too.
1. Open the start menu, search for Disk Cleanup and open it. Alternatively, type "cleanmgr" in the Run dialog box and press Enter.
2. In the Drive Selection window, select (C:) from the drop-down menu and click on the Ok button.
3. Since the old Windows installations are considered as system files, click on the "Clean up system files" button appearing at the bottom.
4. The above action will restart the Disk Cleanup tool. So, select (C:) from the drop-down menu.
5. Now, find Previous Windows Installation(s) option, select the checkbox and click on the Ok button.
6. You might see a confirmation window, click on the Yes button to continue.
6. As soon as you click on the Yes button, Windows will delete the previous installations.
That is all. It is that simple to delete old Windows installation files. Sometimes, you might also see Windows WS and Windows BT folder. These are also old installation and update files. You can delete them to free some more space.
Image credit: Matti Mattila