The eTrex is a now-discontinued handheld global positioning system (GPS) device. A portable GPS such as the eTrex is favoured by hikers, boaters and outdoor enthusiasts as a navigational aid. One feature of the eTrex is the ability to hook up the unit to a personal computer for downloading map images and coordinates. The eTrex is equipped with a computer serial port for this connection. Since most modern computers no longer come with a serial port, you'll probably need a serial to USB adaptor cable. These plug-and-play cables require no special drivers or software.
Press "PWR" on the left edge of the eTrex to turn off the unit.
Turn over the unit to face the back of the eTrex and lift the flap along the top edge to expose the data port.
Connect the serial plug on one end of the adaptor cable to the data port on the eTrex.
Insert the USB plug on the other end of the adaptor cable into any free USB port on your PC.