Image: Matt Elliott/CNET

If you want to install the latest bi-annual update to Windows 10 (the spring update or the fall update), check your available hard disk space before, and then after, the update. Following the update, you may notice that your amount of free disk space has shrunk. That’s because Windows stores installation files from the previous version should you want to revert back to it. That’s fine. But at some point you’ll likely want to stick with the updated version. How do you then get rid of those older folders taking up disk space? Let’s check it out.

SEE: 10 tricks and tweaks for customizing Windows 10 (free PDF) (TechRepublic)

After you’ve installed the latest major Windows 10 update, open File Explorer to the root of your C-drive or whichever system drive holds Windows. You should find two folders: Windows.old and Windows10Upgrade. The Windows.old folder stores all the files from your previous Windows installation should you ever need to go back to it. The Windows10Upgrade folder is generated and used by the Windows Update Assistant to perform the actual update (Figure A).

Figure A

Free up disk space screenshot A

Windows10Upgrade is the easier folder to remove, so let’s tackle that one first. Open Settings and go to the Apps category. At the Apps & Features screen, scroll down until you see the entry for Windows 10 Update Assistant. Click on it and then click the Uninstall button (Figure B). At the next screen, confirm that you want to uninstall the Windows 10 Update Assistant by selecting the Uninstall button.

Figure B

Free up disk space screenshot B

Of course, you can also uninstall the program via Control Panel. In Control Panel, click on the icon for Programs And Features. At the list of installed applications, double-click on the Windows 10 Update Assistant to uninstall it. After the program has been removed, check your system drive and you’ll see that the Windows10Upgrade folder is gone.

Next, it’s time to get rid of the Windows.old folder. Actually, Windows automatically removes this folder after 10 days, but if you don’t want to wait, you can remove it yourself. Go to Settings and then select the System category. Click on the setting for Storage and then click on the link to Configure Storage Sense Or Run It Now. At the next screen, check the box to Delete Previous Versions Of Windows. Then click on the Clean Now button (Figure C).

Figure C

Free up disk space screenshot C

After the cleanup has complete, a Done message appears telling you how much disk space was freed. Check the root of your system drive. You may still see the Windows.old folder though most of its contents will have been removed. To delete it completely, simply right-click on the folder and select Delete from the popup menu. If that doesn’t work or you receive an error, you’ll have to remove it via a command prompt. At the search field, type cmd. Right-click on the matching result for cmd and select Run As Administrator. At the command prompt, type rmdir /s /q c:Windows.old. Check your system drive–the folder should now be gone (Figure D).

Figure D

Free up disk space screenshot D