In some cases the Help author may wish to modify the CSS file or even replace it with a customized CSS file of their own. To make sure that Doc-To-Help does not overwrite the modified CSS file, simply set the GenerateCSS property to False.
1. On the Icon bar, click Project.
2. Select the Help Targets item from the left pane.
3. In the right pane, select the Help target to be edited.
4. In the Property Pane, change the GenerateCSS property False.
Note: Cascading Style Sheets are only used when creating HTML output.