✔ 最佳答案
As the USB cannot be detected ( the light cannot open as well ), it is very likely this USB was out of order due to internal sector errors ( i.e. bad sector ), or the corruption of its own driver ( the driver has files deleted ).
Now the only hope is, if the problem arisen from second mistake ( i.e. driver has crashed ) you can still download it from the official website of memory stick manufacturer, and then it will run properly again. Else, if the problem was due to the first possibility, it is likely you cannot load the files again as you cannot detect it.
You can attempt using another computer to check if the memory stick can be detected, even I am not so optimistic. In the future, please make sure you have at least 2 places more to save your files, one is the external hard-disk ( my recommendation ). This can minimize the lost should one driver has problem.
Hope I can help you.
參考: Mathematics Teacher Mr. Ip