Lock Computer

we'll make a "Lock Computer" Shortcut on your Desktop so you can lock your computer by simply double-clicking on an icon.
On an empty space on your desktop, right click and select "New" then "Shortcut".
You'll see this shortcut wizard Server.
Paste the following line into the "Type the location of this item" box. Click "Next".

%windir%System32rundll32.exe user32.dll,LockWorkStation
This next dialog box will ask for a name for this shortcut. Type in "Lock Computer" or something that makes sense to you. Click "Finish".
Now you'll have an icon on your desktop that allows you to quickly lock your computer without having to go through the process of"control-alt-delete" -> "Lock Computer".