Datasheet

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CHAPTER 1 INTRODUCING WINDOWS VISTA
TIP If a 16-bit application crashes, it will also crash any other program running in the same mem-
ory space. If this happens, you can stop the WOW by using Task Manager and restarting the 16-bit
program. All 32-bit applications will be unaffected by the crash and continue to run normally.
Differences between 32-bit and 64-bit Architectures
From an administrator’s perspective, there are a number of important differences between the 32-bit
and 64-bit versions of Vista. One of the most noticeable differences is that the 64-bit version tends to
run faster because Vista can make use of the full 64 bits of a machine to reduce the number of opera-
tions required to perform some tasks. A 64-bit register also provides better and easier access to mem-
ory. The system also has wider buses to transfer information. In short, a 64-bit system has all kinds of
additional resources that a 32-bit system lacks and Vista makes use of them all.
A 64-bit system is also supposedly more secure because it can’t run any of those 16-bit applica-
tions that caused so many problems in the past. The 16-bit applications relied on libraries that have
all kinds of nonsecure code—a perfect target for hackers who want to gain entry to the system. Of
course, the fact that you can’t run 16-bit applications in Vista means that some applications that did
run in the past won’t run now. You’ll find that game playing (at least older games) is a lot harder
in the 64-bit version of Vista.
You’ll find that having a 64-bit version of Vista can also present some support problems because
now you need 64-bit drivers as well. Many vendors aren’t providing 64-bit drivers yet because
there isn’t enough market appeal for them. The same problem occurred when the 32-bit version of
Windows first appeared. Vendors tried to stay in the world of 16-bits until enough people asked for
the 32-bit drivers. Eventually, every vendor started producing 32-bit drivers and it became hard to
locate 16-bit drivers. The same process is likely to occur with the 64-bit version of Vista. Eventually,
you’ll find that you can obtain all of the 64-bit drivers you need. In the meantime, it pays to shop
carefully.
Table 1.1: User Mode Subsystems
Subsystem Description
Win32 Administers 32-bit and 16-bit Windows programs.
OS/2 Administers character-based OS/2 programs.
POSIX Administers POSIX programs, which are UNIX hybrids that can be run on any POSIX-
compliant system, including Vista. They’re written to a series of application programming
interfaces (APIs) that are platform independent. They control interaction with system
components such as hard drives and memory.
Security Administers system security and manages security tokens, monitors, and passwords. The
user mode portion of the Security subsystem runs only during a user logon.
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