Nikon D3300 - Manual (Page 225)

205 Connections
3
Click Start Transfer.
At default settings, pictures on the memory card will be
copied to the computer.
4
Terminate the connection.
When transfer is complete, turn the camera off and
disconnect the USB cable.
A
During Transfer
Do not turn the camera off or disconnect the USB cable while
transfer is in progress.
A Use a Reliable Power Source
To ensure that data transfer is not interrupted, be sure the camera
battery is fully charged.
A
Connecting Cables
Be sure the camera is off when connecting or disconnecting interface
cables. Do not use force or attempt to insert the connectors at an
angle. Close the connector cover when the connector is not in use.
A
USB Hubs
Transfer may not proceed as expected if the camera is connected via a
USB hub or keyboard.
Start Transfer