I would call OSIsoft support on this one. Having a PC spontaneously reboot is something that we are not going to be able to debug just with questions and answers on the forums. In the meantime, I would check to see if the problem occurs on more than one PC. Spontaneous reboots usually are caused by 1) hardware issues (memory, cpu overheating, power supply, etc), or 2) bugs in kernel mode code (Window and IE) but there isn't any kernel code in ActiveView or SQC themselves or 3) malware/viruses (though this used to be more true than it is now). That doesn't mean that ActiveView couldn't be causing IE to crash, etc. As I said, it's complicated.