Files missing from hard drive.Please Help

[Moosheesha]

I hope I can explain this properly..Here goes...

I have 2 hard drives C: & D:
Today my D: is showing me that I only have one file on it. I have loads of stuff on there from music to photos. If I go to my computer and right click properties on D: it says72.9GB used & 76GB free. I have dont the thing through control pannel and file options to show hidden files but it doesnt work.
I know the files are still on the hard drive because this has happened before & I searched the drive (right click on my computer page & search on the drive) & the files were found. But its not working this time.
I have 2 short cuts on my desktop for 2 of the music folders on D: & if I open the short cuts the music is there and plays fine. Is the drive I use to download anything to from the internet so have sent a folded there but even thats not showing.
I'm not clued up on computers & I'm at a total loss. Its frustrating me & I cant seem to find help from googling the problem.
Oh I have also just added a folder to the D: then came out of it & tried going back to my computer then D: & its not there, also copied a folder from C: to D: and thats not showing either.

Please help me