Problem with accessing files.

Ok, long story, really annoying problem. I had 2 hard drives at one point, one that had windows XP home edition on it, and another to store all my media and files. Just so happens that the hard drive with Windows died, so what I did was just installed Windows Home Ed. onto the hard drive with all my media. Now windows is working and everything, however I cannot access ANY of the files that were on the hard drive before windows was installed. They are all still there, but when I try to open them I get various error messages, mostly they all say something to the effect that access is denied or I don't have proper privileges to open the file. Anyone out there know what's going on? Many thanks.