The Screets Windows keys

Ctrl + Escape or Win : Display start menu.
Shift + F10 or AppsKey : Display context menu.
Win + E : Open Windows Explorer.
Win + R : Open Run dialog.
Win + M : Minimize all windows.
Win + Shift + M : Undo minimize all windows.
Win + D : Toggle minimize all windows.
Win + B (XP only) : Activate system tray. Arrow keys select, Enter double-clicks, and AppsKey or Shift + F10 right-clicks.
Win + L (XP Only) : Locks keyboard. Similar to Lock Workstation.
Win + F or F3 : Open Find dialog. (All Files) F3 may not work in some applications which use F3 for their own find dialogs.
Win + Control + F : Open Find dialog. (Computers)
Win + U : Open Utility Manager.
Win + F1 : Open Windows help.
Win + Pause : Open System Properties dialog.
Win + Tab : Cycle through taskbar buttons. Enter clicks, AppsKey or Shift + F10 right-clicks.

Win + Shift + Tab : Cycle through taskbar buttons in reverse.
Alt + Tab : Display CoolSwitch. More commonly known as the AltTab dialog.
Alt + Shift + Tab : Display CoolSwitch; go in reverse.
Alt + Escape : Send active window to the bottom of the z-order.
Alt + Shift + Escape : Activate the window at the bottom of the z-order.
Alt + F4 : Close active window; or, if all windows are closed, open shutdown dialog.
Shift while a CD is loading: Bypass AutoPlay.
Ctrl + Alt + Delete or Ctrl + Alt + NumpadDel (Both NumLock states): Invoke the Task Manager or NT Security dialog.
Ctrl + Shift + Escape (XP Only): Invoke the task manager. On earlier OSes, acts like Ctrl + Escape.
Printscreen: Copy screenshot of current screen to clipboard.
Alt + Printscreen : Copy screenshot of current active window to clipboard.
Ctrl + Alt + Down Arrow : Invert screen. Untested on OSes other than XP.
Ctrl + Alt + Up Arrow : Undo inversion.

Generic

Ctrl + C or Ctrl + Insert : Copy.
Ctrl + X or Shift + Delete : Cut.
Ctrl + V or Shift + Insert : Paste/Move.
Ctrl + N : New... File, Tab, Entry, etc.
Ctrl + S : Save.
Ctrl + O : Open...
Ctrl + P : Print.
Ctrl + Z : Undo.
Ctrl + A : Select all.
Ctrl + F : Find...
Ctrl + F4 : Close tab or child window.
F1 : Open help.
F11 : Toggle full screen mode.
Alt or F10 : Activate menu bar.
Alt + Space : Display system menu. Same as clicking the icon on the titlebar.
Escape : Remove focus from current control/menu, or close dialog box.


Generic Navigation

Tab : Forward one item.
Shift + Tab : Backward one item.
Ctrl + Tab : Cycle through tabs/child windows.
Ctrl + Shift + Tab : Cycle backwards through tabs/child windows.
Enter : If a button's selected, click it, otherwise, click default button.
Space : Toggle items such as radio buttons or checkboxes.
Alt + (Letter) : Activate item corresponding to (Letter). (Letter) is the underlined letter on the item's name.
Ctrl + Left : Move cursor to the beginning of previous word.
Ctrl + Right : Move cursor to the beginning of next word.
Ctrl + Up : Move cursor to beginning of previous paragraph. This and all subsequent Up/Down hotkeys in this section have only been known to work in RichEdit controls.
Ctrl + Down : Move cursor to beginning of next paragraph.
Shift + Left : Highlight one character to the left.
Shift + Right : Highlight one character to the right.
Shift + Up : Highlight from current cursor position, to one line up.
Shift + Down : Highlight from current cursor position, to one line down.
Ctrl + Shift + Left : Highlight to beginning of previous word.
Ctrl + Shift + Right : Highlight to beginning of next word.
Ctrl + Shift + Up : Highlight to beginning of previous paragraph.
Ctrl + Shift + Down : Highlight to beginning of next paragraph.
Home : Move cursor to top of a scrollable control.
End : Move cursor to bottom of a scrollable control.


Generic File Browser

Arrow Keys : Navigate.
Shift + Arrow Keys : Select multiple items.
Ctrl + Arrow Keys : Change focus without changing selection. "Focus" is the object that will run on Enter. Space toggles selection of the focused item.
(Letter) : Select first found item that begins with (Letter).
BackSpace : Go up one level to the parent directory.
Alt + Left : Go back one folder.
Alt + Right : Go forward one folder.
Enter : Activate (Double-click) selected item(s).
Alt + Enter : View properties for selected item.
F2 : Rename selected item(s).
F7 : New folder.
Ctrl + NumpadPlus : In a Details view, resizes all columns to fit the longest item in each one.
Delete : Delete selected item(s).
Shift + Delete : Delete selected item(s); bypass Recycle Bin.
Ctrl while dragging item(s): Copy.
Ctrl + Shift while dragging item(s): Create shortcut(s).

In tree pane, if any:
Left : Collapse the current selection if expanded, or select the parent folder.
Right : Expand the current selection if collapsed, or select the first subfolder.
NumpadAsterisk : Expand currently selected directory and all subdirectories. No undo.
NumpadPlus : Expand currently selected directory.
NumpadMinus : Collapse currently selected directory.


Accessibility

Right Shift for eight seconds: Toggle FilterKeys on and off. FilterKeys must be enabled.
Left Alt + Left Shift + PrintScreen: Toggle High Contrast on and off. High Contrast must be enabled.
Left Alt + Left Shift + NumLock: Toggle MouseKeys on and off. MouseKeys must be enabled.
NumLock for five seconds: Toggle ToggleKeys on and off. ToggleKeys must be enabled.
Shift five times : Toggle StickyKeys on and off. StickyKeys must be enabled.

Microsoft Natural Keyboard with IntelliType Software Installed

Win + L : Log off Windows.
Win + P : Open Print Manager.
Win + C : Open control panel.
Win + V : Open clipboard.
Win + K : Open keyboard properties.
Win + I : Open mouse properties.
Win + A : Open Accessibility properties.
Win + Space : Displays the list of micr*soft IntelliType shortcut keys.
Win + S : Toggle CapsLock on and off.


Remote Desktop Connection Navigation

Ctrl + Alt + End : Open the NT Security dialog.
Alt + PageUp : Switch between programs.
Alt + PageDown : Switch between programs in reverse.
Alt + Insert : Cycle through the programs in most recently used order.
Alt + Home : Display start menu.
Ctrl + Alt + Break : Switch the client computer between a window and a full screen.
Alt + Delete : Display the Windows menu.
Ctrl + Alt + NumpadMinus: Place a snapshot of the entire client window area on the Terminal server clipboard and provide the same functionality as pressing Alt + PrintScreen on a local computer.
Ctrl + Alt + NumpadPlus: Place a snapshot of the active window in the client on the Terminal server clipboard and provide the same functionality as pressing PrintScreen on a local computer.