I killed my memory card in my camera

I had family reunion pics and a bunch of other stuff on my camera memory card and for some reason it will not upload onto my computer and now when I put the memory card back into my camera it says "picture error" and won't show anything!  I have no earthly idea what I have done to it.  I had some pictures of the hummingbirds perched on a little bush next to my porch.  They are the cutest little things, one of them is a lot larger than the others and he has the green back and wings and then there are the tiny, tiny little ones which are a soft grey on their bellies and a little darker grey on their backs and wings.  When they are perched on the feeder they sometimes make the funniest little noise.  I had never realized that the hummingbirds make a chirping noise.  I really don't know who to ask about the memory card and if there is any possible way to retrieve the pictures on it, I may try taking it to Staples tomorrow to see what they can figure out, if anything.