When I first got my R4, it was working perfectly fine. It had a few games in it already, and those too were absolutely fine. But I tried putting in some games into it and it said I had to delete some ROMs. So I just got rid of some files and games that I thought I didn't need. Then I put it in my DS and it never got past the loading screen. So I deleted more games. But now when I put the card into my DS, all I ever get is a white screen with (in the top screen) the word Menu? in red inside an outline of the shape of the R4. What did I do to my R4? It's totally wrecked, and I can't find the files I deleted!

Someone please help me!