Create A Lock windows Shortcut

Click with right side of your mouse on the desktop then you will see the New option,Click on NEW. Then click on Shortcut now Copy the below code and paste it on Create shortcut window

rundll32 user32.dll,LockWorkStation

then click Next
Enter an shortcut name such as a lock or any other name . Then click on Finish.

now when you click on the shortcut you just made your computer will be locked