Notes about the 3DK 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 3DK file type is primarily associated with 'OS/2' by IBM. This is a floppy disk image. To convert back to floppy disks, find and download the file LDF.COM to get the LOADDSKF.EXE program to unpack files to diskettes. Run LDF from the OS/2 command prompt. A program called LOADDSKF appears in the directory. Type LOADDSKF xxxxx A: to create the new diskette (xxxxx is the file name).