How do you turn it on?

Just kidding. Do you mean the auto restart on system failure? You want to see some blue screens, eh? Anyway... Go to "My Computer-Properties" or AKA "System Properties", click the Advanced tab. You should see "Performace", "User Profiles", and "Startup and Recovery" sections. Click the Settings button in the Startup and Recovery section. Then, under the System Failure section, uncheck "Automatically Restart". If this is what you were refering to, it should help. Good luck!