I would like to modify the WriteToSpreadsheetFile.vi so that it automatically replaces a file, without asking me if it is okay to replace it. i.e. I want my file to be just one line, and not have to append it.
The Write to Spreadsheet File.vi uses Open/Create/Replace File.vi as a subVI. The subVI has a an "advisory dialog" boolean.
Save a copy of the Write to Spreadsheet File.vi with a different name and wire a True constant to the advisory dialog boolean.
If you do not save the VI with a new name and into your directory, the modified VI would be used in any other NI VIs or examples. They might not work properly with the modification. Also your changes would be overwritten at the next LV upgrade.