After the upgrade to Windows 10, you may have noticed a Windows.old folder taking up a lot of space on your hard drive.

The Windows.old folder contains files required to roll back to Windows 8.1 from Windows 10. so, if you delete it YOU WILL NOT BE ABLE TO REVERT BACK TO WINDOWS 8.1 without completely rebuilding. So, make absolutely sure that you’re happy with Windows 10 before you remove this folder.

I have three methods (two and a half) you can try. All three are pretty straightforward, so pick the method that works best for you.

Removal Option 1: Wait

You could just wait and do nothing – 30 days after you upgrade to Windows 10, a built-in utility called Disk Cleanup will go through your hard drive and remove the Windows.old folder automatically.

This is by far the easiest option if you can spare the drive space but it means some of your drive will be tied up until Disk Cleanup runs.

Removal Option 2: Disk Cleanup

If waiting isn’t an option and you need the space back now, you can manually trigger the Disk Cleanup program to clean the Windows.old folder from your drive and reclaim the drive.

To use Disk Cleanup, follow these steps:

• Do a search for Disk Cleanup and run as Administrator the selected Disk Cleanup from the results.

• When the Disk Cleanup program starts, press the Clean Up System Files button.
• Scroll down the list until you find Previous Windows Installation(s) and Temporary Windows Installation Files check the boxes next to each of them. then tap OK (don’t worry about the other checked boxes).
• You’ll get an “are you sure” prompt, select Delete Files.

The Disk Cleanup program will now remove the Windows.old folder from your Surface’s drive. It might take a few minutes, so be patient. You will not need to restart after it’s finished.

Removal Option 3: Elevated RD Command

If for some reason, Disk Cleanup won’t work, you can try deleting the Windows.old folder using the Remove Directory (RD) command from an elevated command prompt.

Here’s how to do it:

• Start an elevated command prompt by right-clicking the Start Button (tap and hold) and selecting Command Prompt (Admin) from the menu.
• In the Command Prompt window, type “RD /S /Q c:\windows.old” (without the quotes)
• Press  Enter.

This option is a half option for me because I got lot’s of access denied messages during the remove process.

Conclusion

If you have to clean up your disk I recommend to use the option 2. I got with this method 22GB free space.