SleepTimer Ultimate is free. It can shutdown the computer after a defined time. Minimum requirement is a Windows XP system. Windows 10 is supported as well. SleepTimer can do other things if the time is reached and is customizable.
Shutdown8 is a simple program that allows users to shut down their computers with a timer. Users can simply add this program onto the taskbar and select the Shut down, Log off, Restart, Timer, Sleep or Hibernate menu.
Daxtar's Shutdown Timer is a minimalistic tool to schedule your System's Shutdown via GUI or command-line. The Tool docks at the Windows System Tray.Discontinued
The project is no longer developed. Last version, 1.0.7, released in August 2007, can be still downloaded from SourceForge
It is a utility allowing to automate shutting the system down or closing specified applications. It is also able to break a modem connection, restart or hibernate the system or even put it to standby mode.
The official website is no longer available. Last version, 2.50, released in June 2012, can be still downloaded from MajorGeeks