STOP Errors are usually the result of a hardware malfunction or device driver issue. It is also possible to receive a Blue Screen Error due to bad system memory, malfunctioning power supply, components overheating, or hardware overclocked beyond its specification. In older versions of the Windows OS you may also receive Blue Screen Errors due to incompatible DLL files.
Since the only option when receiving a Blue Screen Error is to reboot, any unsaved data is lost. With that in mind, it is very important to eliminate these errors to protect your data.