Win-Tab not working

I was showing a friend the neat effect of Win-Tab on Windows 7, but when he tried it, it didn't work! All it does is bring up the Start menu! What could be causing this?

Check that Desktop Composition (i.e. Aero) is enabled:

Control Panel -> System and Maintenance -> System
Advanced system settings
Advanced tab
Performance -> Settings

Does he have Aero enabled?

Windows Flag+Tab does not work when Aero is disabled.

I think due to this, it does not work on Vista Home Basic or Windows 7 starter either.

Is your friend holding down Win when hitting Tab?

Even on my XP work machine, holding Win and pressing any other key doesn't pop up the Start menu; the start menu only pops up if you press Win and then release it without pressing anything else.