If it's recognised everywhere, but not in one device (the reader), that device is suspect.
If it isn't recognised on more that one device, throw it away.
I used my memory card in card reader to get some text files from my friend lappy. I did it two three times bt one day my lappy n my phn are having prblem with that memory card.......Whn i put it in my phn....it hangs n does not respond....as soon as i remove it frm phn, my phn says that preparing sd card.....whn i put it in lappy, my recognize it n says that there are problems with it, scan n fix bt it cant fix.....whn i open explorer it hangs....i tried formatting it using chkdsk n diskpart from cmd bt it also kind of hangs n as soon as i remove sd card from lappy cmd flashes message for commands written whn sd card was attached. Whn i used chkdsk h: /f on cmd it says that 'cannot open volume for direct access'......i hav also used tools like sdformatter n all, they all dont open till my sd card is attached to lappy....as soon as i remove my sd card they open n say no memory card attached............plz help me if there is a way to ormat my sd card or is it corrupted to an extent tht nthing cant be done? bt thn my lappy recognizes it...........hlpppp