alttabsettings classic overidden by Explorer

I have always set alttabsettings to 1 to keep classic alt tab. Since the last Windows update I received, this regedit does nothing unless I kill Explorer, which of course I need for like the Windows key. Any assistance appreciated, I hate alt tab thumbnails, please don't tell me to use the other shortcut as I have been using left hand alt tab with rh on the mouse for more years than I care to say