How to stop the Windows Update process when Windows refuses to stop it?

Many websites, including SuperUser, recommend restarting the Windows Update service in order to fix the common problem of Windows Update getting stuck at 0% downloading.

When I try to stop the Windows Update service (via services.msc), Windows 7 SP1 attempts to stop it, but then after waiting a few minutes, reports that it caot stop the process.

How can I stop the Windows Update process so I can restart it?