couldn't find ds menu dat

HELP.... i attempted to patch a game on my sons r4 card and now when he inserts the r4 into his ds he is getting the message 'Couldn't find_DS_menu.dat' and cannot get into any of his games would somone please tell me what i have done.................... I now have a very unhappy 8yr old. Thanks

why dont u try to download the r4 software again sorry but as i have a tt card i dont no a good site but try the r4 homepage ;D

Reinstall your firmware.