When you receive a reply email from GQ it will have a link in the email. The link will end with your meter's serial number. You need to plug the meter into the computer you are using to read the email (the meter doesn't need to be turned on but should be showing charging). When you click on the link you'll probably get a warning asking if you're sure you want to run this. Say yes. Then a firmware install box opens. Press the Auto Detect to let the software find the serial port. The text area in the box will show Ready to Write or something close to that. Press the Start button in the box and the software will load from there. The meter will reset when complete. Any custom calibration you have done will need to be re-entered.