Blue Screen of Death - Do mention the error code or something from it if you can spot it before the restart
"Blue Screen of Death" is the nickname of the "Stop Error", an error screen which appears when a Windows operating system (NT or later) suffers a fatal low level crash, usually within a device driver.
The error screen consists of white diagnostic text on a blue background typically beginning with:
A problem has been detected and Windows has been shut down to prevent damage to your computer.
Be specific and include as much detail as you can about what you have changed just before the BSOD started happening as well as any error IDs or notices you see on screen at the BSOD dump.