Hello how are you? i`m fairly new to MDL but i noticed your problem with removing Windows.old because i had the same problem but i found a simple solution to easily remove it. Alternatively, you can also use a command prompt to delete files and folders from an earlier installation of Windows. To do this, Run ‘Command Prompt’ as administrator. First you will need to take ownership of this folder, so at the command prompt, type takeown /F C:\Windows.old\* /R /A and hit Enter. Next, in the command prompt, type cacls C:\Windows.old\*.* /T /grant administrators:F and hit Enter. When you run this command, administrators are granted full rights to all files and to all folders. Finally, type rmdir /S /Q C:\Windows.old\ and hit Enter. This will delete the windows.old folder.