>The software for the AccuVote reader runs on WindowsXP, an operating system that hasn’t been supported by Microsoft since 2014, making it vulnerable to crashes.
Not true. What makes an old operating system like WinXP susceptible to crashes is installing and attempting to run newer applications or drivers expected to run on a newer OS or hardware platform. As long as the dedicated machine is only running software compiled to work reliably with the original OS - in this case XP, there is no reason for it to crash. It will remain secure as long as it is not connected to a network where vulnerabilities to the the OS have since been discovered. I have access to an old 80286 machine running MS-DOS that still performs flawlessly.