How to format my memory card?

I bought a memory card from future shop when I bought my DSLR camera which is a Nikon D3100. At first, it was fine when I used it but randomly I tried to use it one day and my camera said "Memory card is un-formatted. Please format." I've tried just putting my memory card straight into my computer and I've also tried putting my camera through the computer using a cord and both ways don't work and I'm not able to fix it. I've googled and I've seen something about a Memory Card Reader that should format it but I wasn't sure if it would work or not because I bought my memory card already formatted. Please help me out! I need a way to get the pictures that were on my memory card back. I don't care if I have to break the memory card, I just need the pictures that were on there.

Try right clicking the card in the Computer menu and click format.

If you will format your memory card, all the files stored will be deleted, but you can use applications such as EASEUS to recover these files