iPod connects then disconnects instantly to computer

when I connect my iPod (i think its a 4th gen) to my windows 7 computer a connection is established but the computer cant seem to hold this connection and it disconnects my iPod. the result is my iPod is constantly connecting and disconnecting (making a very annoying beep) but i am unable to sync or charge using the computer. I cannot see any issues with bent pins and my pod works fine even charging using a iPod player ???