For some applications you don't need the latest and greatest bloatware OS to run perfectly and better. A paired down older version could work better than modern newer versions. Most systems upgrade the OS because they end up having to replacing the hardware. We had a similar situation with one off the RNs sonar sets, it worked perfectly well on 386/486 chips but it was upgraded and caused problems because the MOD couldn't get any more chips to repair the equipment, (the equipment is no longer used by the way.)