There is a problem with your USB port
you should try getting them fixed which is a tough job, but you can try plugging your removable media into another USB port like USB ports in backside of the cabinet.
If you don't find any problem with your USB device then you must have been having problem with your Removable Media (Mp3)
If your MP3 Player is under warranty period then you can look for its repair (can be done if its out of warranty too, but it will charge you extra)
To work around the above issues, one of the below solutions could prove helpful:
Sometimes, simply unplugging the USB device and turning off the computer for twenty minutes and then
restarting may solve the issue. If none of the above options have solved
the problem, check the manufacturer's website for new driver
information. It is possible that your drivers need to be updated. There
could also be a possibility of hardware failure, which needs to be
checked by a hardware expert
Unsecure or Loose Connection
Unplug the presently connected USB device (if any). It is quite possible that the connection is not secure
and has become loose. Re-plug the USB device tightly and firmly into
the USB port. This is one of the most common reasons for an error in
detecting a USB device.
Scan for Hardware Changes in Device Manager
Use the Device Manager to scan for new and recently installed hardware. From the Start menu, select the Run option. In the pop up box, type in Devmgmt.msc and then click Ok. From the Action menu, click Scan for hardware changes.
This will make Windows scan & recognize any new devices that are
installed. Now, close all opened device managers and control panels.
Now, follow the above step and see if your computer detects the USB device.
USB Power Management
Disable power management of the USB hub. To disable the power management on the USB hub, follow these steps; Click Start, and then click Run. Type devmgmt.msc in the popup box, and then click Ok. Expand the Universal Serial Bus Controllers' node, and then follow these steps for each USB Root Hub that is listed.
1. Right-click the USB Root Hub and then click Properties.
2. Click the Power Management tab.
3. Click to clear the Allow the computer to turn off this device to save power check box, and then click Ok.
Note: If you perform the following procedure on a laptop computer, you may reduce the battery life.