2nd Harddrive ADVICE needed. Blank files/folders appearing on full HDD

SonickPlauge

Honorable
Nov 10, 2013
16
0
10,510
I connected a second internal hdd (Which still has all my music and pictures). I know my files are in there, its letting me know that there is 300 gigs free space on the 1TB HDD.
When I open it up the folders are completely blank. I brought up my files once but i forgot what i did to do that. I've been messing with disk management for a bit and cant get anywhere.
If someone can address my problem and help me out I would appreciate it.

I am running Windows 7 and using 2 HDD's.