Access offers only one check box control; WingDings offers several. Don’t limit yourself!
The following Access report shows the default display for a Yes/No field. In this case, an unchecked box means the product is still available; a checked box means the product has been discontinued. Most of the time, the default is adequate and you won’t want to change it. Occasionally, you’ll want a bit more flexibility.
The easiest way to display a check box other than the default is to use the WingDings font, which offers the following check box controls:
To create one of these check boxes, hold down the [Alt] key and press the appropriate numbers on the numeric keypad. Don’t use the numbers along the top of your keypad; you must use the numeric keypad for this technique to work. Then, apply the WingDings font to the resulting character.
When applying the WingDings fault to an Access report (2003, 2007, and 2010), choose two of the above characters: one to represent Yes (True) values and one to represent No (False) values. Now, let’s apply all that to an Access report:

Control Source = Discontinued (or the name of your Yes/No field).
Font Name = WingDings
Width = .25 (You might want to reset this later, but this is a good place to start.)
As you can see, the No (or false) values now display an X instead of being empty. The Yes (true) check boxes still display checks, but the style is different. If you want to display just checks for Yes values and nothing for No values, leave the first Format component blank (step 5). In addition, experiment with other format attributes such as color.