How do I access hidden & system folders/files in Windows 7?

I suffered a corrupted boot sector on my old XP hard drive. I have a brand new Terabyte C: drive in place and Windows 7 Ultimate installed.

Now the process of recovering system settings, bookmarks, favorites, etc from the old drive, which is still readable as a E: drive now. I found where Firefix stores its user settings in Documents and Settings/Mozilla Firefox. I can copy the file there. But I cannot access Users/James/ on the new Windows 7 drive. It says access denied even if I am logged in as Admin. Right clicking the folder doesn’t seem to offer any way to change that access. How do I let myself in to hidden and system files on my own computer?