Downloaded brushes not working.

Alright, so I'm working on a graphic that is for a game. I'm a complete Photoshop newb. I needed blood brushes, so I went online and downloaded some. Only one set of blood brushes works, and all I did to make it appear in my brush tips list was to click on the ABR file. However, the other brushes I downloaded don't show up. I did what the instructions that came with the brushes said and put it in my Brushes folder. However, it still won't show up. Any idea what I'm doing wrong?

BTW, I'm using Photoshop version CS2 on a Windows XP.

Did you restart Photoshop?

Are the Brushes compatible with CS2? If they are made in CS3 they probably won't work.