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+W : to close the current window
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 Rich Edit 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).
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.
Numpad Asterisk: Expand currently selected directory and all subdirectories. No undo.
Numpad Plus: Expand currently selected directory.
Numpad Minus: Collapse currently selected directory.