Windows 8 Shortcut Keys

Start Screen

Win Toggle the new start menu on or off
Win+D Switch to classic Windows desktop
Win+, Peek at desktop
← Select the tile to the left
→ Select the tile to the right
Win+PgUp Move tiles to the left
Win+PgDn Move tiles to the right
Win+B Switch to classic Windows desktop and select notification tray

Starting Programs

Win+1 Open the first program on your Quick Launch bar
Win+2 Open the second program on your Quick Launch bar
Win+n Open the nth program on your Quick Launch bar
Win+Q Open Application Search panel
Win+F Open File Search panel
Win+E Open Explorer
Win+R Open the Run window [more info]
Ctrl+Shift+Esc Open Windows Task Manager

Charms, Share, Search, Settings, and other Panels

Win+C Open Charms panel to search, share, and change settings
Win+H Open Share panel
Win+I Open Settings panel to change settings for the current application, volume, wireless networks, shut down
Win+P Open Projection panel (generally used for laptops connected to projectors)
Win+K Open Devices panel for connecting to a projector or other device
Win+Z Open the current application's application bar
Win+Q Open Application Search panel
Win+W Open Settings Search panel
Win+F Open File Search panel

Managing Windows

Win+Tab Switch between Metro applications
Win+. Snap current Metro application to the right
Win+Shift. Snap current Metro application to the left
Win+J Cycle through snapped Metro applications
Alt+F4 Close the active window
Alt+Tab Switch to previous active window
Alt+Esc Cycle through all open windows
Win+T Cycle through applications on taskbar (showing its live preview)
Win+M Minimize all open windows
Win+D Toggle showing the desktop
Win+↑ Maximize the current window
Win+↓ If the current window is maximized, restore it; if the current window is restored, minimize it
Win+← Dock the current window to the left half of the screen
*If it is already docked left, it is moved to the right half of the screen
*If it is already docked right, it is restored to its original size
Win+→ Dock the current window to the right half of the screen
*If it is already docked right, it is moved to the left half of the screen
*If it is already docked left, it is restored to its original size
Win+Shift+← Move current window to the left monitor (with dual monitors)
Win+Shift+→ Move current window to the right monitor (with dual monitors)
Win+Home Minimize all but the current window (press again to undo)
Win+Y Peek at the desktop
Win+[Plus sign] Zoom in
Win+[Minus sign] Zoom out
Win+V Cycle through toasts
Win+ShiftV Cycle in reverse through toasts

Taskbar Modifiers

Shift+Click Open a new instance of the program
Ctrl+Click Cycle between windows in a group
Middle Click Open a new instance of the program
Ctrl+Shift+Click Open a new instance of the program as Administrator
Shift+Right-Click Show window menu

Viewing Folders With Explorer

Alt+P Show/hide the preview pane
Alt+← Go back
Alt+→ Go forward
Alt+↑ Go up a directory
Alt+D Move focus to address bar
Alt+D, Tab Move focus to search bar
Alt+Enter Open the Properties window of the current selection
Ctrl+Mousewheel Change the view type (extra large, small, list view, detail, etc.)
Alt+P Show/hide the preview pane

Other

Win+L Lock computer
Win+B Move focus to notification tray (the right-most portion of the taskbar)
Win+O Lock device orientation (landscape/portrait); for devices with a gyroscope
Win+Space Switch input language and keyboard layout
Win+Enter Open Narrator
Win+Pause Open the System Properties portion from the Control Panel