problems with image packs

Whenever I download an image pack, I can always see it when I do to My Pictures. But when I'm on my Photoshop and I go to File-Open-My Pictures, the image pack I downloaded isn't there. Why can't I see the image pack when I do this? I can't even find it when I do this, and it's really annoying 'cause then I can't use the image pack.

What should I do? Or am I doing something wrong?