I have a Lenovo Yoga Pro 2... worst computer ever. Running Windows 8.1.
Anyway, recently, my ALT+F4 no longer works anywhere. It won't close windows.
On the other hand, CTRL+F4 still works (i.e., with closing individual Chrome tabs), and ALT+Tab works, which indicates to me that there is nothing wrong with the ALT or F4 keys individually.
Thanks for any advice!