External HD not showing in finder though visible in disk utility.

Hi guys,

This is my first post here though i wouldn't consider myself a mac noob. I always read everyone else's posts but really couldn't find one like the problem i'm having here...

I lent my friend my external hard drive (which is mac formatted) and he used it in his imac then when i got it back from him, i plugged it in to find that it wouldn't show up in finder. It shows in disk utility and you can use the "reveal in finder" option to open it (and beyond that make a shortcut on the desktop to that window) but in general it is now a hidden file on finder.

My iTunes all runs from it and that works fine but what bugs me is that I can't find it in my time machine back ups which go onto another (larger) external hard drive. It appears that the files must be there because the back up is 650GB and I only have a 200GB internal HD but I can't find it.

Could somebody please help me either make the HD visible in finder again or tell me where these files may be within my "macintosh HD" folder in the backup please?

Also, in disk utility it say that no owners are enabled and the "verify disk permissions" button is blanked out.

Thanks in advance!

Verify disk permissions is a startup disk function. And it only verifies things that were installed with the Mac installer.
Using Disk Utility, "mount" the drive.

Thanks Gsahli, I didn't realise that about disk permissions. It says that it is already mounted when I look in disk utility since it only gives me the option to unmount it. That sounds write as I can access the files, it's just a hidden folder and there seems to be no way of changing this back.