E250 Problems With Connecting

I’ve had my e250 for a 2 years, but have only started using it recently. A couple of days ago I put 50 something songs on it and it connected to the computer just fine, now a week later i try to connect to the computer again, and it does  connect but only for a few seconds then the screen fades and the e250 restarts itself. this happens repeatedly if the player is hooked up to the computer. wHat should i do so I can start connecting to the computer?