Can I toggle Alt + Tab's functionality?

Solution 1:

You can use AutoHotKey. The script in question would be:

!Tab::
return

to disable the key, or to rebind it something like (rebinding to F8):

!Tab::F8

Use F9 to toggle on Alt + Tab:

IsEnabled := 1
F9::
if (IsEnabled = 1) {
    IsEnabled := 0
} else if(IsEnabled = 0) {
 IsEnabled := 1
}
return
#If IsEnabled
!Tab::
return