How to force a "confirm shutdown" in Windows 7

Not exactly what you were looking for, but you could Enable the Shutdown Event Tracker.

In Registry Editor, navigate to

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Reliability

Name:ShutdownReasonUI (REG_DWORD)

1=enable 0=disable

You can right click on the Windows button, select properties and assign the function of the "shutdown button" to default to Log Off. This was you may accidentally log off instead of shutting down but it is not as detrimental as shutting down rather than logging off.

Are you aware that immediately to the right of the shutdown button (in the start menu) you can press the arrow and you'll find the dialog tree you're looking for? You can also access the "log off" button by pressing ctrl-alt-del.

Finally, if you want it to appear on the start menu without clicking the arrow, you can adjust the local machine policy by typing in the search/run field, "gpedit.msc" and pressing enter. Then navigate to "User Configuration", "Administrative Templates", "Start Menu and Taskbar". Modify the policy "Add Logoff to the Start Menu." Change it to enabled. Reboot.

Good luck!

I've not used it myself, but ShutdownGuard was designed to handle exactly this situation. (Binary downloads are available on the releases page.)