The following are different ways to lock your workstation.
1. Windows-L
Hit the Windows key and the L key on your keyboard. Keyboard shortcut for the lock!
2. Ctrl-Alt-Del
Press Ctrl-Alt-Delete. On the menu that pops up, click Lock. Boom, done.
3. Start button
Tap or click the Start button in the bottom-left corner. Click your user icon and then select Lock.
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4. Auto lock via screen saver
You can set your PC to lock automatically when the screen saver pops up. Go to Control Panel > Appearance & Personalization > Change screen saver and then check the box for On resume, display logon screen. You can also set a time for how long your PC should wait before starting the screen saver. Now, when you exit the screensaver, you'll need to enter your system password to get back in.