Windows 10 Tip

 If you cannot get into Windows, hold down Shift key when restarting, then go to Troubleshooting options.

Another Windows 10 Quick Tip

If you have many windows open and want to focus on one in particular, while holding down the left mouse key, grab the title bar with your mouse pointer, then shake back and forth to minimize all other windows. If you want to bring the other windows back, just shake the first window again and all will be right back to normal. Using the Alt and Tab keys together still works to switch windows.