Try this 1
1) Try Connecting it to different USB ports.
2) Connect it to the USB port --> Click on Start --> In search box, type
devmgmt.msc and press Enter. "Device manager" will be opened.
If you notice any yellow mark then right-click on it --> Select "Update" and follow
the instructions. If there is no yellow mark then click on the white area in that
window. Now click on "Action"--> Scan for hardware changes. Check if its able
to detect your device.
If the problem still exist then close the "Device manager" window and
go to step 3
3) Click on Start --> In search box, type cmd and press Enter.
"Command Prompt" will be opened. Now enter the below commands
[ Note : You can copy the command --> Right-click in the Command Prompt and
paste it. ]
set devmgr_show_nonpresent_devices=1 --> Press Enter
cd\ ---> Press Enter
cd windows\system32 --> Press Enter
start devmgmt.msc --> Press Enter
"Device Manager" window will be opened.
Now in the device manager, click on "View" --> Select "Show hidden devices"
Now expand all the nodes by clicking on "+" symbol. If you find any greyed
entries --> Right click on it --> Select "Uninstall".
Uninstall all the greyed entries from all the nodes --> Restart your PC --> Now
try connecting your Mp3 player.
4) If the problem still exists then check your USB cable.