SPLAT won't import MIDI files from non-CW source...

I'm trying to import midi files (or just one) into a midi track from a local folder containing a Computer Music MIDI pack.  They are .midi files, while CW's are .mid files, but my understanding is that it shouldn't make a difference. 
 
I've tried dragging from the Windows folder (and the curser "acts" like it will go, i.e., it's the plus sign, not the circle/slash), but nothing appears in the MIDI track.  As a test, I tried doing the same from the CW content folder, and the MIDI imported just fine.
 
I've tried file/import/MIDI from Sonar and when I direct it to correct folder, it doesn't even see the files.  I tried copying the CM MIDI folder into the CW Content folder, and the CW browser sees the folder, but nothing inside it (even though right clicking "properties" within CW, it indicates the folder is not empty).
 
I've right clicked "properties" on the CW and CM files, and they are both MIDI sequences, but CW can't see the CM files.
 
Using a laptop, as I'm on vacation (which is slowly going down hill troubleshooting), and the onboard soundcard and Wavetable Synth as the MIDI output (no input option).
 
Does anybody have any suggestions?
 
Thanks in advance.

I would change the extension to mid. I can't recall ever seeing a file with that extension. I may have I just don't recall it. It could have been created on a Mac. They don't use the extension.   

Thanks folks. I had never seen a .midi file either, but the internet said they're the same...

I gave a thought to changing the extensions, but quickly let it go, probably because I'm lazy, but it does seem like the thing to try, so I'll go do it now. Can I batch change extensions of it works?

Thanks folks, that's extremely helpful - I've been out of pocket, but will try the fix as soon as I get home.