HP 3900 series - Manual (Page 12)

4 Connect to the printer
The printer connects to the computer with a universal serial bus (USB) cable. The
computer must be running Windows 98 or later to use a USB cable.
For instructions about connecting the printer with a USB cable, see the setup poster
that came with the printer.
Note A USB cable might not be packaged with your printer.
10 HP Deskjet 3900 series