You need to install the pyboard driver to use the serial USB device.

The driver is on the pyboard's USB flash drive, and is called ``pybcdc.inf``.

To install this driver you need to go to Device Manager

for your computer, find the pyboard in the list of devices (it should have

a warning sign next to it because it's not working yet), right click on

the pyboard device, select Properties, then Install Driver. You need to

then select the option to find the driver manually (don't use Windows auto update),

navigate to the pyboard's USB drive, and select that. It should then install.

After installing, go back to the Device Manager to find the installed pyboard,

and see which COM port it is (eg COM4).

More comprehensive instructions can be found in the

`Guide for pyboard on Windows (PDF) <http://micropython.org/resources/Micro-Python-Windows-setup.pdf>`_.

Please consult this guide if you are having problems installing the driver.

The best option is to download the free program PuTTY:

`putty.exe <http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html>`_.