I'm sorry about the issue. Is it the Coolpix model P520?
What's the model of your Windows 10 computer? Is it a desktop or laptop?
With the camera powered on and connected to the computer, does it show anything on the camera's screen? Does it show the camera device in File Explorer (This PC) on the computer's screen?
Can we do a remote support session, so I can troubleshoot the issue directly on your computer together with you?Please reply at the box below. Thank you,