USB stick isn't recognized by the computer

[MarpoOcknew]

2 days ago my memory stick was working fine in class. Since then it hasn't worked on any machine I have tried it on. It just comes up that is unrecognized. It's a 4gb Sandisk if it helps

The drive doesn't have a case on it so i can see that there are no breaks or anything so I'm not sure what could be wrong with it.

I could really do with getting the files off it as it, as it's my uni course work that is due in a week.

 

[MarpoOcknew]

Is there a light on the stick that glows after plugging it in the computer? Also is the drive listed in my computer and disk management.?

The light comes on at the start but then goes off once it says its unrecognized. It's not shown on My Computer or Disk Management. It does show on Device Manager but just as an unknown device and telling it to update its drivers does nothing.