Oct 12 2006

Why Computers Crash

Personal computers will crash—it’s inevitable. Here’s why and what you should look for when it happens to you.

Your computer may crash again—maybe in two days, two weeks or two months. It’s impossible to say when and nearly impossible to avoid but here are the most likely reasons your computer will crash and how to minimize the impact:

The power supply fails. It’s unlikely that a failed battery, power cord or transformer will cause a crash. The power supply is another story. It converts alternating current to direct current (AC to DC). If it falters and begins to produce a noisy electrical signal, it can crash the computer.

Cooling mechanisms become damaged. PCs have heat sinks, usually small pieces of aluminum attached to the microprocessor. Heat sinks absorb and dissipate heat into the air. A fan blows the heated air out through a vent. If the heat sink or fan fails, the microprocessor’s temperature will rise above the safe limit: 55 degrees Celsius. Your computer’s random-access memory (RAM) or central processing unit (CPU) will overheat, and your PC will crash.

You can help your PC stay cool—and take some of the load off its cooling mechanisms—by keeping the area around your CPU, especially the fan vent, clear.

The hard drive crashes. Jarring the computer can damage the head mechanism, which reads digital information from the disk surface. A less visible cause of hard drive failure is rooted in the drive’s sectors, where information is stored. Every drive leaves the factory with bad sectors, tiny portions of the drive surface that cannot record data. But all drives also have extra sectors to make up for these imperfections. However, sectors can go bad at any time. Should those newly failed sectors contain data vital to the PC’s operating system, the computer will crash.

A General Protection Fault occurs. GPF messages can occur for many reasons, but memory violation may be the most common. An application may try to use a protected area of RAM. This is the way Windows prevents an application from overwriting the OS itself or other applications.

An application may fail to recognize that the OS has refused its request for more RAM and proceed as though it had been granted. It attempts a memory-intensive operation, the RAM is not available, and the computer crashes.

A programming glitch can cause Windows to err in accessing the PC’s memory and crash itself.

GPF-causing bugs are all too common and sometimes a result of programming errors in the OS or applications. Often, downloading software patches, small bits of new code designed to fix the bug, from the OS vendor’s Web site or adding more RAM can help.

Thrashing: PCs can only multitask so much. If too many memory-hogging programs are run at once, the OS gets overwhelmed. Several programs must then fight for the same resources—namely, reading and storing data from memory. The system takes so much time switching back and forth, trying to accommodate each program, that little actual processing gets done.

Because the system usually recovers if left on its own for a short time, thrashing, as it is known, is not crashing; it just feels that way. When it recovers, close some applications to prevent further thrashing.

A new driver may cause conflicts. Adding hardware devices or software to a PC requires a software driver, a program that enables the new software or hardware to run. If the drivers aren’t well-tested to prevent conflicts, they can cause the OS to crash.

If you’ve recently installed a new application or added a new hardware device, remove the drivers, reboot and add them one at a time to see if one of them is at fault.

DLL versions may clash. Dynamic Link Libraries are small programs used by multiple larger programs to accomplish tasks such as selecting a font. When you install a new application, it may install its own, older version of a DLL file, overwriting a newer version already on your PC. Functions in other applications that depend on code in the newer version not only no longer work, but also may crash the computer.

crash (krăsh) v. crashed, crash•ing, crash•es The sudden failure of an application, a computer operating system or a hardware device such as a printer.

Computing Errors Cause Chain Reaction