Blue screens are generally caused by problems with your computer's hardware or issues with its hardware driver software. ... A blue screen occurs when Windows encounters a “STOP Error.” This critical failure causes Windows to crash and stop working. The only thing Windows can do at that point is restart the PC.

Why is Windows BSOD blue?

A blue screen error (also called a stop error) can occur if a problem causes your device to shut down or restart unexpectedly. You might see a blue screen with a message that your device ran into a problem and needs to restart.

Is blue screen bad?

When Windows senses that something could cause real harm, it stops everything, resulting in the infamous Blue Screen of Death. ... A BSoD can be a symptom of a hardware problem. In that case, it might look as if the error itself caused the problem. Although a BSoD won't damage your hardware, it can ruin your day.