Solution: Spybot - Search & Destroy Crashes Your Windows 7 Operating System and Shuts Down Computer
Does Spybot-S&D (Spybot-Search & Destroy) crash your Windows operating system and your computer? Do you find that part-way through a Spybot spyware scan your computer mysteriously switches off? Then check to make sure that you do not have any additional security software running in real-time in the background. And if you do have other security scanners running, such as anti-virus software, shut them down before you make a scan with Spybot S&D.
For example, if you have Threatfire (from PC Tools) running in the background, then "suspend" its operation. Or if you have Microsoft Security Essentials running in real-time, then go to the Microsoft Security Essentials settings and turn off Real-time Protection.
If you are running Avast, AVG, Norton, PC Tools, Trend Micro, or any other antivirus software in real-time, in the background, so that the software is constantly checking your computer for threats, then shut those real-time security processes down before you start a Spybot scan.