Micro SD card problems

Today i bought that Game n' Music ([link]) thing for my DS, it was really simple and i was listening to music on my DS almost right away. It comes with a Micro SD card that you put inside of a USB 2.0 card reader and insert into your USB port in your PC. I am having a problem with the Micro SD card, I put some files on it and I think i might have taken it out of the USB card reader without safely removing the hard drive first. I'm not sure, but whatever I did the Micro SD card can't be read now and because i have to plug it into the USB card reader to plug it into the computer I cannot format it. Can someone please tell me how can i get it to read the Micro SD card without just buying a new one? (i can't buy them around here without buying like 3 other SD card that are completely useless packaged with it) If you need anymore information just ask me.