This option is found on the "Windows" tab in "WinHelp Compiler Options".
At the Top is the Window name. Use the drop down arrow to select other window names. You can use the [+] button to add more windows or the [X] button to delete the current window. The only window you cannot delete is the "Main" window, which is reserved.
Below this is the Title, which will show on the title bar of the window when compiled.
There are three tabs which are loaded for each window. On the Background Colors tab you can select a color for the Nonscroll and Scroll regions by clicking on the drop down arrows of the color boxes.
Size and Position
These fields decide where your help file will display once compiled and how wide and tall it will appear. These dimensions do NOT relate to the size of your screen resolution. They are relative to a maximum of 1024. If you have a setting of Left = 0, Top = 0, Width = 1024 and Height = 1024, will give you a help file that fills the screen completely.
Auto-size height, which cannot be set for the "Main" window, will reduce the height of your help text area, if possible. Maximize window will open the help file maximized. The "Keep on Top" option will keep your help file above all others.
In the first set of buttons you can optionally have either "Contents and Index" or "Help Topics". The rest of the buttons speak for themselves. These are the only buttons that WinHelp provides.