Blue Screen

Yesterday, i've got my laptop underwent 'blue screen'
Anybody knows what it is?

Let u s check the answer. I took this from wikipedia :

The Blue Screen of Death (also known as a stop error, BSoD, bluescreen, or Blue Screen of Doom) is a colloquialism used for the error screen displayed by some operating systems, most notably Microsoft Windows, after encountering a critical system error which can cause the system to shut down to prevent damage.

Bluescreens on NT-based Windows systems are usually caused by poorly-written device drivers or malfunctioning hardware. In the Win9x era, incompatible DLLs or bugs in the kernel of the operating system could also cause bluescreens. They can also be caused by physical faults such as faulty memory, power supplies, overheating of computer components, or hardware running beyond its specification limits. Bluescreens have been present in all Windows-based operating systems since Windows 3.1; earlier, OS/2 suffered the Black Screen of Death, and early builds of Windows Vista displayed the Red Screen of Death after a boot loader error.