Notes about the DFG file extension:
To open this file type, a required software must be installed. Without it you only see a Windows message "The following file cannot be opened
" (Windows 7) or "How do you want to open this file?
" (Windows 10) if you double-click the file. There click on "More apps"
and choose a suitable software to view such files on your PC or from email attachments.
The DFG file type is primarily associated with 'Data Flask' by Interscape. Data Flask is a spreadsheet application designed to retain data type, source, and key information. Information imported into a Flask Grid File (*.DFG) becomes an independent, disconnected copy of the data from the source. Data from a wide variety of sources is supported, ranging from Unicode text files to SQL databases. There is a free viewer available; look for the link on the program's site. This file keeps data type, source and key information in addition to a value.
Detailed information for file extension DFG:
File classification: Spreadsheet
To change file associations press Windows Key
and then Apps and Features
> Default apps
> Choose default apps by file type
Invalid file associations could be the result of underlying issues within your Windows PC.