If you are trying to use 3D, go find an old XP laptop, take it offline for security and dedicate it to XP. I remember running 3D on W98. On that version, you needed a printer port to run it. The full 3D is a digitizing program, the light one gives some control, and 3D also had a file assistant that just transferred files.
If the machine is a 1+ or a Rose, it uses cards. Amazing designs has a card reader that will work. They used the HUS format.
If it's the first Designer, it saved files in a slightly different manner. If you can find a program that works with that model Designer, then you don't need 3D. I think it used floppies. There are other programs for just customizing and resizing designs if you don't want to digitize. I used Buzztools at one time and there are now more to choose from.