It's second time it happened to me: 1. Two years ago, I installed Intel Active Monitor application http://intel.com/design/motherbd/active.htm for my Intel D850MD mainboard. Within following days after, a persistent alarm in the application warned me on an increase of temperature coming from "System Temperaure"(cooling tab), happening only when running certain programs. Once, while away from PC, I found the machine 'dead'. No electric current, simply dead. Needless to say I stayed breathless. I went to tech service and 'fortunately' technician found the PC's Power Supply Box overheated and dead. I explained him problems started after installing IAA, but he was unable to find a reason of overheating. I bought a new power supply box, uninstalled IAA and all went back to normal. 2. Last week I decided give a try and install F-Secure antivirus 2005 (full uninstalled previous one before). After reboot, performed a system scan with it. While scanning, I heard a loud 'beep' sound coming from into PC case and it powered down on it's own. Went to tech service and, again, the PC's power supply box 'dead'. Same history This is VERY strange to me. I know a new hardware installed may conduce to a general system electric failure but I have no idea on why a software??? PLEASE, any advice, thoughts, ideas or whatever to help me to understand this system behavior. Thanks