Files are hidden? Windows 10 cant read my files?

Hi I updated to windows 10 about a month a go and its all been fine. I did a clean install of the C: drive and left the my other one alone, its my main storage drive. They are separate. Now I noticed that all the files that are in the folders are gone but still taking up space. Every word document, picture, music and movie file still takes up space. there are 400 gigs of entertainment hidden. I tried to show hidden files but that only shows folders.
I am at a loss. Dont know what to do.