Page 324 - DCAP103_Principle of operating system

Unit 10: Introduction of Windows and its Programming

Despite many portability features with regard to the code, hardware, language, etc., in one respect Notes
Windows 2000 is less portable than NT 4.0—it runs on only two platforms, the Pentium and
the Intel IA-64. Originally NT supported additional platforms, including the PowerPC, MIPS,
and Alpha, but over the years, Microsoft dropped one after another for commercial reasons.
Like previous versions of NT, Windows 2000 comes in several product levels, this time:
Professional, Server, Advanced server, and Datacenter server. The differences between all these
versions are minor however, with the same executable binary used for all versions. When the
system is installed, the product type is recorded in an internal database (the registry). At boot
time, the operating system checks the registry to see which version it is. The differences are
shown in Figure 10.2.

Figure 10.2: The Different Versions of Windows 2000

Version Max RAM CPUs Max clients Cluster size Optimized for

Professional 4 GB 2 10 0 Response time

Server 4 GB 4 Unlimited 0 Throughput

Advanced server 8 GB 8 Unlimited 2 Throughput

Datacenter server 64 GB 32 Unlimited 4 Throughput

As can be seen from the figure, the differences include the maximum memory supported, the
maximum number of CPUs (for a multiprocessor configuration), and the maximum number
of clients that can be served. The cluster size relates to the ability of Windows 2000 to make
two or four machines look like a single server to the outside world, a useful feature for Web
servers, for example. Finally, the default parameters are tuned differently on Professional, to
favor interactive programs over batch work, although these can easily be changed if desired.
One last difference is that some extra software is provided on the servers and some extra tools
are provided on Datacenter server for managing large jobs.
The reason for having multiple versions is simply marketing: this allows Microsoft to charge big
companies more than they charge individuals for what is essentially the same product. This idea
is not new, however, and hardly unique to Microsoft. For years, airlines having been charging
business passengers much more, not only for Business Class, but also for Cattle Class if they
want the luxury of buying the ticket a day before the flight instead of a month before the flight.
Technically, the way the version differences are maintained is that in a few places in the code,
two variables are read from the registry, ProductType and ProductSuite. Depending on their
values, slightly different code is executed. Changing these variables is in violation of the license.
In addition, the system traps any attempt to change them and records the attempt at tampering
in an indelible way so it can be detected later.
In addition to the basic operating system, Microsoft has also developed several tool kits for
advanced users. These include the Support Tools, the Software Development Kit, the Driver
Development Kit, and the Resource Kit. These include a large number of utilities and tools for
tweaking and monitoring the system. The support tools are on the Windows 2000 CD-ROM
in the directory \support\tools. The standard installation procedure does not install them,
but there is a file setup.exe in that directory that does. The SDK and DDK are available to
developers at msdn.microsoft.com. The Resource Kit is a Microsoft product in a box. There are
also various third-party tools available for snooping on the Windows 2000 internals, including
a nice set available for free at the Website www.sysinternals.com. Some of these even provide
more information than the corresponding Microsoft tools.

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