Show all Notes: Automatically fill all squares with all possible notes.

Update Notes: When you place a number, the game will automatically remove all notes for that number in other squares in the same row, column, or cell (as those squares are no longer a possibility for that number).This is shown as a small number in the corner of the numeric 'keyboard' at the bottom of the screen. Show Remaining: This will show you how many of each number have not yet been placed into the puzzle.Block Duplicates: This will prevent you from placing a number in a row, column, or cell if that number already exists elsewhere in that row, column, or cell.Show Mistakes: When you place a number incorrectly, it is immediately highlighted in red.Highlight Houses: When you select a given square, it will highlight the rest of that row, column, and cell to make it easier to see.The game has a number of assistance features built into the game that are available in the options menu: You'll also get quite a bit better just from practice as you learn to recognize patterns that you've seen before. There are many good resources for learning how to do Sudoku puzzles.

I'm not going to give a detailed description of how to figure that out.

Microsoft irregular sudoku