Unable to open the file in USB

I stored many files in a USB drive many months ago. 

I tried to open the files in USB, but found that all the files become 1 file called ''ReadyBoost''. It has 1.6M KB. I tried to open the "ReadyBoost" file but cannot. 

I used some USB recovery software on the USB. It able to scan that there are many files inside the USB, i.e. not deleted but seems hidden somewhere in USB. 

I tried some cmd command like áttributes -s -h /s /h but still cannot locate the files. 

What should I do?

L