Notes about the TO_BE_DELETED 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 TO_BE_DELETED file type is primarily associated with 'No Specific Program'. This extension is used as a marker for files which are, as you might expect, to be deleted. It is typically used as a temporary marker by programs which later come back and clean up by deleting the file(s) so marked. Sometimes one will get missed or a program will terminate unexpectedly and leave the file. It should not hurt to just leave the file alone with the expectation that the same program will be run at a later time and clean up after itself. Before deleting the file outright one should rename it and see if any program complains about its absence. If, after a month or so, nothing complains then it should be safe to delete the file.
Detailed information for file extension TO_BE_DELETED:
Primary association: No Specific Program
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.