Sadly, RAW format appears on devices which may have some hardware issue. RAW may mean that the drive is currently not really recognized from the system. There are so few thing you could do to restore information from a RAW file format. It seems to me that you have no data in the flash, but if you do try connecting it to some Linux OS.
If you have no important data in that USB, I recommend you to replace it. It is very important to use a reliable device for your data.
Hope this helps