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1.1. The Big Picture
The first few releases of Microsoft Windows in the early 1980s were
little more than clunky graphical application launchers that ran on
top of the Disk Operating System (DOS)
(see Chapter 6 for details). Version 3.x,
released in the late 1980s, gained popularity due to its improved
interface (awful by today's standards) and ability
to access all of a computer's memory. Being based on
DOS, however, it was not terribly stable, crashed frequently, and had
very limited support for networking and no support for multiple user
accounts.Soon thereafter, Windows NT 3.0
("NT" for New Technology) was
released. Although it shared the same interface as Windows 3.0, it
was based on a more robust and secure
kernel , the underlying code upon which the
interface and all of the applications run. Among other things, it
didn't rely on DOS and was capable of running
32-bit applications (Windows 3.0 could
only run more feeble 16-bit applications).[1]
Unfortunately, it was a white elephant of sorts, enjoying limited
commercial appeal due to its stiff hardware requirements and scant
industry support.
[1] A
bit ,
or binary digit , is the smallest unit of information
storage, capable of holding either a zero or a one. 32-bit operating
systems like Windows NT and Windows 95 were capable of addressing
memory in 32-bit (4 byte) chunks, which made them more efficient and
powerful than a 16-bit OS like Windows 3.x.
In 1995, Microsoft released Windows
95. Although based on DOS like Windows 3.x (it was known internally
as Windows 4.0), it was a 32-bit operating system with a new
interface. It was the first step in migrating the enhanced capability
of the Windows NT architecture to the more commercially accepted,
albeit less capable, DOS-based Windows line. Soon thereafter, Windows
NT 4.0 was released, which brought the new Windows 95-style interface
to the NT line. Both of these grand gestures were engineered to
further blur the line between these two different Microsoft
platforms. Although both operating systems sported the same
interface, Windows NT still never garnered the industry support and
commercial success of Windows 95.As time progressed, the lineage of Microsoft Windows became even less
linear. Despite
its name, Windows 2000 was not the successor to
Windows 98 and Windows 95;
Windows Me, released at the same time, had
that distinction. Instead, Windows 2000 was the next installment of
the NT line; it was actually known internally as Windows NT 5.0.
Windows 2000 was particularly notable for being the first version of
Windows NT to support plug-and-play, which was yet another move to
combine the two platforms.Then came Windows XP, known internally as Windows NT 5.1.[2] Although it's
technically merely an incremental upgrade to Windows 2000, it has
been positioned as the direct replacement to Windows Me, officially
marking the end of the DOS-based Windows 9x/Me line. Windows XP is
indeed the long-anticipated operating system designed to finally
unify both lines of Windows, bringing the bulletproof stability of NT
to home and small business users, and the industry support of Windows
9x/Me to corporate and power users.
[2] Type ver at any command prompt to see for
yourself.
