Sansa screen seems!!

after i turned on my computer i put it the sansa express into my labtop. it was charging then i turned off my labtop and when i took out the mp3, on the screen it says READING and it shows a pic of the mp3 and the computer but nothing else happens. when i tried putting the mp3 back into the computer it says that the computer cannot recognize the usb…it said that it’s malfunctioned…what can i do??? plz help

press the slect button and the (+) volume button and it will reset