How to check how much memory is used up?

??? OK, so like right after I get an account on this site, POOF! I can't put any more NDS games on my flash cart. I'm guessing the 2GB space is taken up, but I want to be sure. Is there a way to check how much memory I've used up on the 2GB space? ???

You use Microsoft Windows right? If so, then when the microSD is attached to your computer, open My Computer, then right click on the removable disk icon and select Properties. :D There you'll be shown the card's memory usage.