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.

Try previewing files using this method:
http://www.cakewalk.com/Documentation?product=SONAR%20X3&language=3&help=Tutorial2.3.html
 

Treefight
They are .midi files, while CW's are .mid files, but my understanding is that it shouldn't make a difference. 
 

I think you're right, but have you tried renaming a few to .mid to see if it makes a difference?

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.   

You can do a lot with Windows by renaming an extension to what it wants.

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?

I changed the extension of a known-to-work-properly MIDI file from .mid to .midi, and SONAR no longer recognized it. So I think there's your answer.

+1, .midi can be assigned to Windows easily, but an application must also recognize the file extension for it to import. If you have a large number of files, you can batch rename them via the cmd prompt (or alternatively via a batch renaming utility, but I cannot think of any offhand).
 
Quick edit to make less painful for you. If you use Windows Explorer to find the highest folder that contains your "*.midi" files you can use the following command to rename them all from the cmd prompt.
 

1. Click Start, type Search/Run and type "cmd"
2. Right click and run as administrator
3. Type forfiles /p "[path of highest level directory of midi files]" /s /m *.midi /c "cmd /c rename @file @fname.mid"

For me, this directory is "F:\Cakewalk Content\Audio Library" so typing the following at the command prompt would change all *.midi files to *.mid files (including all subdirectories of F:\Cakewalk Content\Audio Library):
 
forfiles /p "F:\Cakewalk Content\Audio Library" /s /m *.midi /c "cmd /c rename @file @fname.mid"
 
 
 

Funny, when ever I look for midi files if I see the extension .midi I assume it's a virus and I carry on elsewhere... I figure if it does not have .mid it is something else of evil intent. 

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