Serial No.*:

*To get serial number of each handheld or PC
Go to Screen 1 (black screen which lists farmer names, test dates etc.)
Type K followed by E followed by Y
(you will not see the letters appear as you type)
You will see screen with ENTER NEW KEY FOR XXXXXXXXXX
Type these characters into the Serial No. box above.
Then type the 10 characters you get back from this website into the handheld or PC where prompted. Press ENTER & that's it.