SudokuWorks for Windows

The description of SudokuWorks - Play With New Friends

An unlimited supply of puzzles. Nine different grid sizes from 4x4 to 16x16. Play with numbers or letters of the alphabet. Seven different background skins, plus change colours to suit your mood. Play against the clock and compete to get in the roll of honour. Five levels of difficulty. Pencil in your working as you go with right mouse button, confirm your choice with the left button. Unique coaching modes to help you learn or solve the trickier puzzles. Enter the puzzles from the newspaper and play them as a normal game, or have the program solve it for you and show you the answer. You can also print out puzzles to play on paper, and save a game to return to later or to mail to a friend. Full undo/redo history so you can backtrack through your game.