There are several keyboard accelerators (or "keybinds") in Chess.
Ctrl+N: New. Not case sensitive.
Ctrl+s: Save. This lowercase s is case sensitive, so make sure Caps Lock is off, and do not hold Shift.
Ctrl+S: Save As.... This uppercase S is case sensitive, so hold Shift or use Caps Lock.
Ctrl+O: Open.... Not case sensitive. The letter "oh," not the number zero.
Ctrl+Q: Quit. Not case sensitive.
Ctrl+U: SFX folder.... Not case sensitive.
Ctrl+i: Icons.... Not case sensitive. Show here as a lowercase i to differentiate it from a lowercase L.
Ctrl+←: Step back (undo). Uses the "left" arrow.
Ctrl+→: Step forward (redo). Uses the "right" arrow.
Ctrl+↑: Beginning of match. Uses the "up" arrow.
Ctrl+↓: End of match. Uses the "down" arrow.
F1: View help.
F5: Refreshes the board. Use this if the game's window is too small or too large to neatly hold the board and status message.