SD card works on camera, but not computer?

I have an SDHC Card, and I use it with my Nikon camera almost every day, and every day I put my SD card into my HP Pavilion laptop and it works, and I store the pictures in different folders on my computer. Recently, I have to push the SD Card in pretty hard until it reads, but today, no matter how hard I try, it won't work. I also tried the SD card in my brother's laptop, and it wouldn't read. So the card won't work in two laptops, but it still reads perfectly fine on my camera. I don't have the USB for the camera.

The plastic strips that separate the metal connectors on the bottom have a habit of coming loose. Remove them and then insert the card into the slot slowly.