What am i doing wrong??

First timer!!
I'm trying to get a downloaded game from your site to work on my son's ds. I have downloaded the rar file, and followed the instructions for extracting!
I have transferred the nds file to the memory card and inserted it into the ds.
When i turn on the ds it just comes up with a red card with "menu ?"
What am i missing or doing wrong?
Would appreciate some help!!
Many Thanks
J22

Uhmm... What flashcart do you have? What roms did you download? These two informations is crucial if you need help. :)Oh, one thing. Did everything work fine before you put the new rom in?

Hi there,
Game downloaded =2905-Call of duty world of war(u)(Venom)
Flashcard = Transscend 8GB micro sd hc. Plugged into an R4
Console works fine with other games in! :-\
J22

Your MicroSD is missing the firmware (menu) files for the card.You need to either visit the official website for your card and download them, or go to www.linfoxdomain.com/nintendo/ds and download them there.Then just extract the files and put them on your MicroSD.

;DThanks for help
Sorted ;D
J22