Family Historian Program Data Folder
The sub-folders hold such items as Custom & Standard Diagram Types (FHD), Fact Sets (FHF), Queries (FHQ), Reports (FHR), Text Schemes (FHT), etc.
Windows 2000 & Windows XP
The data folder is C:\Documents and Settings\All Users\Application Data\Calico Pie\Family Historian\.
Windows Vista, 7, 8, 8.1 & 10
The data folder is C:\ProgramData\Calico Pie\Family Historian\.
Note that this is \ProgramData\ and NOT \Program Files\. \ProgramData\ is the replacement for \Documents and Settings\All Users\Application Data\.
Windows Vista/7/8/10 in Crossover/Wine on Mac/Linux
The data folder is C:\Users\Public\Application Data\Calico Pie\Family Historian\.
In the above folder definitions C: is the drive with Windows installed in 95% of systems, but in some it may be a different letter.
If you don't see this data folder, it may be hidden, so you will need to adjust some settings. A Google search for Show hidden folders in Windows together with your version of Windows, will list tutorials illustrating alternative methods as summarised below.
Windows 2000, XP, Vista, 7
Open Windows Explorer (Windows key + E) and choose the Tools → Folder options menu, or Organize → Folders and search options menu, then select the View tab. In the Advanced settings ensure that Hidden files and folders is set to Show hidden files, folders and drives. While there it is advisable to untick Hide extensions for known file types so that the entire filename and extension is always shown.
The same dialogue can be reached via Start → Control Panel → (Appearance and Themes →) Folder Options → View.
Windows 8, 8.1, 10
From the Start screen click the Windows/File Explorer tile, or from the Desktop open File Explorer or This PC (Windows key + E). Select the View tab and tick the box Hidden Items in the ribbon. While there it is advisable to tick File Name Extensions so that the entire filename and extension is always shown.
The same dialogue as above for earlier Windows versions can be reached via Control Panel → (Appearance and Themes →) File Explorer/Folder Options → View → Show hidden files and folders.
Note that the Windows (C:) drive will be found under This PC within File Explorer.