Correct syntax for Windows 10 html file

[FrankLidgad]

Can you provide an example to add a html file to var newTabURL = "file:/// in Windows 10 please?
For instance my html file is located at c:\web\main.html

In your notes you do not mention using a drive letter and also I am unsure of the direction of slashes in order to work correctly.

(I am using Firefox ESR)