[filmscanners] Re: Switch from Win98SE to XP?

["Anthony Atkielski" <anthony@atkielski.com>]

Laurie writes:

> Alas Anthony, you are taking the term much too
> literally.

It's extremely important to distinguish between system failures and
application failures, even for the most unsophisticated user of a computer.

A system failure means everything crashes; the computer will interrupt
everything and show something like the infamous "blue screen of death" (a
plain blue screen covered with digits), and absolutely nothing will work
until the computer is turned off and on again or the reset button is pressed
(in some cases, the computer will reboot itself, but it will start right
from the beginning, as if you had just turned it on).

An application failure means that you get a nasty error message saying that
a program is no longer working.  Other parts of the system may or may not
continue to work, but the system itself generally does not crash.  Under
inferior operating systems, such as all of the Windows 9x operating systems
and the old MacOS, a failing application _might_ mess up the system enough
to make it necessary to reboot; in even rarer cases, the failing application
might cause a system failure.  However, in new operating systems such as
Windows NT/2000/XP or Mac OS/X, an application failure is limited to the
application--the rest of the system continues to run.

These distinctions are important because they determine what you must do to
fix the problem, and where to look for blame or responsibility.  System
failures always indicate a defect in the operating system (even if they are
caused by applications, unless the application is "trusted").  Application
failures are defects in an application, and have nothing to do with the
system.  There's no point in blaming Windows for a failure of your Widget or
Frammis application, nor will changing to any other operating system fix
such a problem, since the problem is not in the operating system to begin
with.

> This may require one to shut down the program
> in question and restart it; but it does not
> always result in needing to reboot.

In that case, changing operating systems isn't going to help, is it?  Which
is why it is important to make the distinction.

FWIW, when system crashes do occur, the most common causes are (1) bad
device drivers and (2) buggy application programs with special privileges.

Bad device drivers are a problem because hardware vendors must write drivers
for their hardware, and the operating system is required to trust device
drivers completely (because they must access hardware directly), and most
vendors write very poor device drivers.  As a result, a lot of device
drivers are filled with bugs, and when the bugs are sprung during execution,
the entire system crashes, because the device driver is using doing
something very sensitive with the hardware and the operating system cannot
afford to risk continued operating once a driver hits a bug.  A partial
solution is to certify drivers, which Microsoft does now, but not every
vendor gets his drivers certified.

Buggy application programs are not a problem on stable operating systems
such as the NT family of Windows (NT/2000/XP) or Mac OS/X, UNLESS they have
special privileges, which some programs do (anti-virus stuff, some games,
etc.).  Programs with privileges that fail may bring the system down.
Programs without privileges may crash, but the system will stay up.  On
inferior operating systems such as Windows 9x and the old MacOS, even
unprivileged programs may crash the entire system (because these primitive
operating systems treat _every_ application as privileged by default).



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