After you have selected a pair of text files for comparison and pressed the Compare button or double-clicked an entry on the Compare Directories dialog, the differences will be displayed in either a pair of windows or a composite one.
A useful tip is that if you wish to increase the text size used to display the differences, press the Ctrl and + keys simultaneously.
To decrease the text size, press Ctrl and - simultaneously.
To return the text to its default size press Ctrl and 0 (numeric zero).
You can also right-click on the window and bring up a Print dialog.