@Nancye wrote:Nothing worked. I tossed it. Thanks for eveyone's replies.
With ANY memory card or USB device, there is a risk if you simply pull it out of the reader when you have finished using it. Basically, the software on the computer creates links to files it is using on the card, and if the card is removed without closing those links the File Allocation Table (FAT) is corrupted and the card can be rendered permanently unreadable. The symptoms you outlike are definitely in line with that.
On a Windows machine you should go through the process of ejecting the card. Close any apps that have accessed the device, then either:
From the File Manager, RIGHT-CLICK on the device name on the menu map and from the pop-up menu select Eject. If it is successful the device will disappear off the list.
OR...
In the tray (bottom right by the symbols for time etc. There is a ^ symbol. Click on that to display options and select the Eject Device symbol (see image). If successful it usually comes up with a message to the effect you can umplug the device, but if not click on it again and if the device is no longer displayed, you are successful.
