Photoshop Question

I use PS7, and I've had it for awhile now. I had quite a lot of brushes uploaded, so you can imagine that I was seeing red when I opened it up to discover that all by brushes were gone. I figured it would be a one time thing, so I uploaded what brushes I needed to do what I was working on, and planned to re-upload the rest the next day. Well, I open up Photoshop today, and it's back the same way it was before. All my brushes are gone, and all the default settings are selected. What's wrong and how can I fix it?