How can I delete a non-empty directory from the command line?

If the lab is expecting the traditional Windows `rmdir` command, use the recursive option: `rmdir /s D:softwarearch98`. Add `/q` if the lab allows it and you want to skip the confirmation prompt: `rmdir /s /q D:softwarearch98`. The `/s` switch is what tells it to remove the files and subdirectories too.

In PowerShell, `rmdir` is normally an alias for `Remove-Item`, so the PowerShell form would be `Remove-Item -Path 'D:softwarearch98' -Recurse -Force`. However, if the exercise only permits the listed commands, it may specifically expect the Windows-style `rmdir /s` syntax rather than this cmdlet.

First verify that the path exists and that you're typing it exactly as shown with `dir D:software`. If the files are hidden or read-only, list them with `dir /a`; the lab may expect you to use `attrib` to clear those attributes before removing the directory. Also make sure you're running the command in the environment the exercise requires, since PowerShell and Command Prompt interpret switches differently.