How do I open a harddrive on my computer I just plugged in?

Kari asked:


I put a different harddrive in my computer (a harddrive from a couple of years ago) so i can get some pictures off of it. When my computer booted up, it has all my same files and everything from my new harddrive on it? I went to my computer thinking maybe my harddrive would open up from there but it didnt? Where can I get my old stuff from when the harddrives already in my computer?