i tryed it again with my husbands computer and the cards are working now!!! Yeah finally.
But they are only working on my Nintendo DS lite and DSi XL V1.4E
And on my DSi XL V1.41E the card is still not working.
It's weird that I can't open or download stuff with my new laptop but can do with my husbands "old" computer".
But the most importand is that it's finally working.