Win + L Quickly locks your computer, very useful.
Win + D Displays your desktop by minimizing all your open windows .
Win + R opens up the Run window so you can launch and application or paste a URL.
Win + T shows the first Item on your task list you can then navigate through them by using the arrow keys.
Win + U opens up the Ease of access window, here are some useful tools such as magnifier, but you can easily zoom in by pressing Win + ‘+’ and zoom out by pressing Win + ‘-‘ this is very useful specially when you are doing a presentation, which I do a lot of.
Win + P is also very useful for presentations. it gives you the projector shortcut keys
Win + S is really cool, if you are familiar with Snag it, well it does basically the same thing allows you to grab a portion of your screen then pastes it in One Note.
Win + E Opens the explorer window.
Win + F opens of the search window.
Win + X launches the Mobility window from there you can control the volume, check battery status, Wireless setting, projector settings and Sync settings
Win + N launches OneNote
Now some really cool shortcuts, some times I want to dock one of my apps to the right and another one to the left all you have to do is press Win + right or left arrow Key, this is really cool when you use multiple monitors.
Win + Up arrow will maximizes current window, Win + Down arrow will restore the current window if it is maximized, hit it again and will minimizes the active window.
you can maximize, restore or dock the active window simply by dragging it to the top or sides, or just grab any window by its title bar shake it a bit and it automatically will minimize all the other windows.