Excel's Insert-Comment command lets you annotate a cell by typing a comment. Once the comment is created, you can change its formatting. To do this, right-click the cell and select Edit Comment from the Shortcut menu. When the comment is displayed, click anywhere on its border to select the entire comment object. Now you can use the standard toolbar buttons to change the font, text size, or colours.

To change the default formatting of your cell comments (so you don't have to repeat that process each time), you need to go outside Excel. These comments are Windows' ToolTips, and they appear whenever your pointer hovers near toolbar buttons as well as in several other environments. Select Start-Settings-Control Panel and double-click the Display icon. Click the Appearance tab and choose ToolTip from the Item list (see FIGURE 1). Use the controls to change the background colour, text size and colour, and text attributes (bold or italic). Click OK to close the dialogue box. Comments you've already formatted will not be affected by this change. Remember, all your ToolTips will be formatted with the new scheme.