Todays memory cards for cameras and phones get cheaper and more affordable every few months and make room for huge amounts of pictures.

Lower prices are nice, until the quality suffers and suddenly the card isn’t readable anymore and all pictures are lost forever.

In some cases the card can still be recognized by Windows but windows doesn’t show any photos or data or asks you to format the card.

As a last resort there is always the possibility to use a low level picture recovery software like Digicam Photo Recovery to try to recover the pictures.

If the computer doesn’t recognize the card, you could try to insert it into a simple USB pluggable card reader. The less features the reader has, the better. So try to get one that is small and only has the ability to exactly read your card type.

When this also isn’t helping, there is a thing you could do before you throw it into the trash.
You might check the metal strips and see if they are rusty or dirty, or (at your own risk) put the card into a waterproof fridge bag and place it into the fridge (sometimes the cold realigns the particles and lets you read the data a last time)

So maybe there is a way to get your pictures back if you act quickly. This is also a case to buy your recovery software and a small cardreader in advance. Better safe then sorry.

Give it a try: Digicam Photo Recovery picture recovery software