A lot of users use the various shortucts to control their computer applications so as Windows. But not a lot of them use the Windows Key (WinKey) what is a shame, because as the name says it’s especially convenient while you are using the Windows OS. The Windows Key is the key with the Windows logo left bottom on your keyboard between the Ctrl and Alt. If you press it you should see the Start menu shows up.
WinKey+L (as Lock)

Using this key you can easy lock-up your Windows account if you need to get out of your PC for a while. But remember you have to set the password for your Windows’ account otherwise it’s useless. And anybody can easily log-in back to your account. This tip is the same as you would press Start->Log Off->Switch User.
WinKey+E (as Explore(r))
If your favourite application to browse the computer isn’t something like TotalCommander, you are probably use just right Windows Explorer. And in that case it comes convinient for you the next tip to run the Windows Explorer using the WinKey+E. It’s the same as you would open the My Computer.
WinKey+R (as Run)

If you need to run some Windows’ application, you can use the Run dialog. Don’t have to go through Start->Run, just press WinKey+R. Fast, intuitive and easy.
WinKey+D (as Desktop)
If you need just to look up at your desktop and you have opened a lot of windows, there’s no need to minimize them all one by one. This key combination helps you to display the Desktop and when you press the WinKey+D again, all windows are back at the same place. Really useful mostly if you need to open some file located on the Desktop.
WinKey+F (as Find)

A lot of time people are something finding in their computers, so don’t bother even with finding the Find button in Windows. Just press the WinKey+F and the Find window will show up.
If you know any other useful key combinations share your tips with the other users in the comments. Once these key combinations all are working since Windows XP you can use them in all subsequent Windows verions.