Turn off Serial Keys. If you are upgrading from Windows XP and currently using Serial Keys with alternative input devices, ...

Turn off Serial Keys. If you are upgrading from Windows XP and currently using Serial Keys with alternative input devices, such as single switch or puff and sip devices, turn off Serial Keys and install another solution before upgrading. To turn off Serial Keys, open 'Accessibility Options'. On the 'General' tab, under Serial Key devices, clear the 'Use Serial Keys' check box. See the Microsoft Ease of Access website for where to install solutions so you can keep using your devices with this version of Windows.%0