Memory stick can't be read

Question

My stick is "Kingston Datatraveler 8GB". It's was good at first. Later, (may be because of viruses) when i travel my data to other computers through it, the data are shown with unreadable characters. And vice versa. I inserted this stick into TV to listen music, and after ejected, none of the computers can't read it. (I don't try again with TV.)
Here's detail......
When I plug my stick into my computer, the computer knows whether the new device is installed. But when i click the it to open or explore it, computer asks to insert the disk again. When i expand it beside the panel, i can't see any folder. But when i look my USB's memory, the whole stick is used fully as it's filled with blue color. But both of the information of Used space and Free space show 0 GB.
Plz help me how to handle with it.