I havn't got a clue wot im doing

Please please please can someone help me i am going crazy!
I recently bought two r4 cards from r4 cards.co.uk one for my daughters ds and one for my dsi, i followed their on line installation guide to install the software onto my card and that seems to work as i get the menu settings on the ds, however, when I download any games from romulation and put them onto my card when i put the card into my ds the game is not there I can't find it. I've tried reformatting the cards and re installing the software but nothing seems to work. please can someone help me I am a complete novice and need an idiots guide to all the computer jargon!!!!!thanks Emma

did you unrar the file. If you didn't get winrar, to open rar files, you should end up with a .nds file

When you get a game you have to extract the RAR file to get to the proper
game file. Check if the file says .nds if it says .rar then it won't work so
in order to extract the .rar file you need WinRAR, you can download this
software anywhere just Google WinRAR Download. Once you have installed
WinRAR and extracted the .rar file it will create a folder with the name of the
game, then insert the Micro SD Chip into the computer and Copy then Paste
the .nds file onto the chip, then Insert the chip into the R4 card and then
turn on the DS and start R4, click on the file that has your game's name. There are rumors that R4 does not work on a DSi but go ahead and try it
if it's not working then just notify me and I'll see if I can help. Regards, Retropower

off topic: I've read a few of your posts, why do you keep saying regards retropower when we can plainly see Retropower just there?