Tim Childs wrote:
In Windows explorer, it is possible to set a flag under
View-Options_filetypes to determine if a CSV file (or any
other type of file) opens automatically on being
downloaded.

You mean the "Confirm open after download" flag?

Experiment suggests that

HKEY_CLASSES_ROOT\Excel.CSV\EditFlags has value 65536 if the flag is
NOT set (and 0 if it is). I suspect it might be a bit-map and so you
should probably only change the 1 bit in the key value.

Bill Manville
MVP - Microsoft Excel, Oxford, England
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