Reformatting and Time Machine Issues

Hey, I just recently reformatted my macbook (snow leopard) aluminium unibody so I can have it working faster. I was told that my time machine would be able to store everything on my "old" computer. So I didn't worry to get another harddrive to backup the semi important stuff, like photos and music. However, I cannot access my old photos and music or old archived files from my time machine. Going into time machine, everything except for Macintosh and applications are all greyed out. How can I access my old files that are located in desktop and such?