My new 250gb files not showing

hello everybody

I bought my WD 3 weeks ago, then i packed up all my music folder into it, when i tried to check if everything is ok, I found the folder inside but not all the music, my music is oraganised in alphabet order folders inside big folder, so i started to check every folder, some has music, some hasnt, im not sure why is that happening, any idea?

Cheers

You can check if the files are hidden, check the link below for the steps.

http://windows.microsoft.com/en-US/windows7/Show-hidden-files

Hello mate

Thank you for your respond,

I just tried that and none of the folder is hidden, the thing is i dont see the MP3 files in some of the folders.

the thing my entire music collection was saved at my friend PC, so i asked him to pack it up and took us about 30mins to get into my WD passport, when i went home i couldnt see mp3 files inside some folders (I use macbook) I returned back to my friend, plugged the WD in his PC everything is ok and I can see all mp3 files that i couldnt see on my Mac

it is confusing and frustarting

Regards