November 04, 2012, 1:22 PM — Here's how you can delete the Windows.old folder after upgrading to Windows 8. This might save you a significant amount of hard disk space.
1. Press Windows-R on your keyboard.
2. The run box will open.
3. Enter this command into the run box and hit Enter.
4. The Disk Cleanup tool will load.
5. Click on "Clean up systems files" button.
6. Check the checkbox next to "Previous Windows installations."
7. Click the OK button and the Disk Cleanup tool will delete the Windows.old folder.
For more, see the original article at the link below.