Notes about the 4DR 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 4DR file type is primarily associated with '4th Dimension' by 4D, Inc.. The 4th Dimension product line offers a range of Mac OS and Windows products that can be used together to create a fully integrated, Web-enabled, cross-platform database development solution, or as individual components. This is the resource fork; .4DD is the data fork.
Detailed information for file extension 4DR:
File classification: Database
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.