My wireless devices (bluetooth and Marvell wifi adapter) disappeared today immediately following windows update that included firmware update to 5/19/15. They do not show up in Device Manager at all. I thought first that this is the way to force the switch to Windows 10 which I was dragging my feet to update. However, that did not help. I proceeded with factory restore and after that even with option "Show hidden devices" they do not show up as if they never existed. Any advice would be greatly appreciated. Is there a way to downgrade firmware?