Since upgrading to Windows 10 I cannot wake up my computer from sleep mode. With Windows 7 and 8.1 all I had to do was tap any key and the computer would wake up. Now that doesn't work. I have to press and hold down the power button to force a shut down and then restart, sometimes two or three times before anything happens. This problem only appeared after I installed Windows 10. How can I fix it? I have a Toshiba Equium Laptop which has never had this problem before.