1. Windows Logo + L

Locks the PC instantly.

2. Shift + Delete

Deletes and bypasses the Recycle Bin entirely.

3. Alt + F6

Quickly switch between multiple open windows within a given application.

4. Shift + CTRL + N

Create a new untitled folder from within explorer.

5. Windows + M

Minimize all open windows to the taskbar.

6. Windows + Spacebar

All of your open windows will turn transparent so you can see right through them until released.

7. Windows + Shift + Left or Right Arrow

Moves window from one display to another.

8. Windows + 1, 2, 3, etc.

Press Windows + 1 to launch the first pinned app in your Taskbar (from left to right). Windows + 2 launches the second one, Windows + 3 launches the third one, and so on.

9. Windows + T

Scroll through apps that are already open on the taskbar, and hit Enter to select the one you want.

10. Windows + (+/-)

Zoom in for a magnified view.

http://www.maximumpc.com/article/features/10_coolest_windows_shortcuts_you_never_knew_about

– Main.FredPettis - 2011-10-01