Intro to Windows NT

This document is meant as an intro to NT4 on workstations for advanced computer users. It is made as a short technical comparision with Windows 3.

Basic NT info

Memory model

PCs using DOS or Windows 3 are using an old memory model which may cause trouble. DOS is limited to addressing 640 kB (fig 1).

Windows 3 and 95 can access more memory after a rather complicated shuffling of memory. Those systems start on DOS mode, then the CPU switches to "protected mode", accessing more memory and "virtual machine" mode. This usage of memory blocks, and the lack of protected memory areas for applications, leads to a greater risk for system crashes.

The practical effective memory limit for Windows 3 seems to be about 16 MB. It is claimed that Windows 95 does not handle memory efficiently above about 40 MB, but I cannot confirm that. (fig 2).

Windows NT – as well as OS/2, Linux and Mac OS – has a flat addressing of the RAM memory, which reduces trouble (fig 3). Individual programs under NT run in a protected memory area, so that they can't cause a system crash.

Technical info

Requires at least a 386 with 16 MB RAM. Recommended for Intel Pentium or compatible CPU with at least 32 MB RAM. Preferably 48 or 64 MB RAM if you will use several large applications simultaneously.

NT uses a flat memory model addressing up to 4 GB RAM. NT can theoretically use a maximum addressable hard disk space of 16 exabyte (16x10 exp 18), i.e. 16 000 000 000 gigabyte.

NT uses preemptive multitasking. That means the OS has more control over each process. It is impossible for an application to take over and lock the whole system, but this also means a certain system overhead. If one application crashes, it can be terminated with CTRL-ALT-DEL without crashing the system.

Compare with Novell Netware, which usually uses cooperative multitasking. That is more efficient than preemptive multitasking but a bad NLM (Netware Loadable Module) may crash the whole system.

System setup is saved in the register, which can be accessed by REGEDIT and REGEDT32. Installed 32 bit applications can be removed from the Control panel, which you reach from Start | Settings.

NT uses HAL, a "hardware abstraction layer", between hardware and system code. Thus it’s relatively easy to port NT to other processors. Below is an illustration of how that works.

user (yes, that's you)

applications

drivers

NT operating system kernel

HAL

hardware

NT 4 uses the same good system for switchable character sets and keyboards, as Windows 95. It’s e.g. easy to produce text in Russian mixed with Latin alphabet text. It works with different code tables for Cyrillic characters.

Accounts

After a normal new NT installation, 2 accounts are created on the local machine, Administrator and Guest. The Guest account is disabled by default and the Administrator account will prompt for a password during the first logon.

In a network installation, each user must be defined, before the computer can be used. In this user definition, username and password should be set as the same as in the network. If the password is entered here, the user should be present and do it. If the password field is left blank here, the user can enter it during the first login. But then the user must be informed how that is done.

Novell Netware

Novell 3 servers do not support long file names without an extra NLM installed. In such a case, documents should be given a name of max 8 characters.

The Start menu

The appearance of the Start menu can be customised by right-clicking on Start, followed by Open, Open all users, or Explore all users. This is mentioned below, under security.

Important keyboard commands and Help

These work in almost the same way under Windows 3.11 and Windows 95. Any user who is not used to Windows multitasking should always have the taskbar visible. It is very easy to by mistake start e.g. Word twice, working on the same document. That can be a quick way to destroy your data.

If you are not used to Windows 95 or NT, you should know that several functions can be reached by right-clicking the mouse. Try it yourself, and you will learn.

If you need help, try the built-in help system. To find general help on NT, click on Start, Help, and Contents. In various applications or dialogs, you can press F1 or open any menus marked Help or ?.

File systems

Windows NT has 2 built-in file managers: This Computer and Explorer. It’s important to know how they work.

If you want, you can create a document directly on the desktop. All you need is to right-click the mouse. The file is then stored in directory C:\WINNT\PROFILES\username\DESKTOP. This is not very obvious, but it’s similar in Windows 95.

On the desktop you can see both "shortcuts" and icons representing real files. You should be careful about dragging the latter to the trashcan.

To check the status of your hard disk, open My Computer, right-click on drive C: then choose Properties and Tools. Finally choose Error checking. It‘s a good habit to do this check every week or so.

Windows NT supports 2 file systems, FAT and NTFS. When you use FAT, you actually use something called VFAT. That is an extension to the FAT system, allowing for long file names. The same system as in Windows 95. It works fine until you use an old 16 bit Windows or DOS file utility. Then the file name is truncated. Therefore you should always use document names with distinct beginnings, even when you use long document names.

Files deleted with a 32 bit program are temporarily stored in the Recycle bin, which is more convenient than the old UNDELETE command.

If you run out of hard disk space, NT offers a possibility to compress the disk. This is similar to Stacker, DoubleDisk, DriveSpace, etc. I do not recommend compressing hard disks. It’s slower, and depends on a special driver. Also, you can’t access that drive directly from a normal boot disk.

If you need high security for local files on a PC, I recommend the NTFS file system. When you use NTFS, you can hide or lock certain files or directories for certain users.

If the previous file system was FAT, NT has a convert command. A conversion can be made without loss of data. Thus an existing NT installation can be converted to NT later.

NTFS has a built-in function for hotfix, similar to the Novell Netware system. Bad sectors on a hard disk are marked out automatically, protecting data written to disk. For most users, the FAT file system gives a good enough security.

If you use the FAT file system, you can alternatively boot NT, Windows 95 (if that is also installed) and DOS, on the same partition, thanks to the Microsoft menu system.

NT, as well as Windows 3.11 and Windows 95, supports the Workgroup function, where you can choose to share directories on your hard disk with others.

NT Security

System password

If you enter the computer's BIOS setup, you can configure your computer so that a password must be entered before accessing the computer, even if you boot with a DOS diskette. Such a protection can however be disabled by opening the computer case.

NT password

NT can never be started without logging on. Without an account and password, nobody can enter the system without a boot diskette. This is an important improvement to Windows 3 or Windows 95.

Modifying desktop and Start menu

You can modify the Start menu by right-clicking the Start button. Those changes will then apply only to the account, that you are logged in to.

Except for the security offered by the NTFS file system, you can also use the Policy editor, to hide certain menu choices for certain users. The Policy editor is not part of a normal NT Workstation installation, but I mention it here as an example of possible security functions. The Policy editor is mainly for a network where the server is running NT Server, but it can be used also on NT Workstation. The first time you start Poledit, go to Options and load a template. The Common template is usually enough. If you then choose Open registry, any policy changes will be saved to the local machine, for the particular account you have logged on. Then save your changes. One example: You can hide Run, DOS Prompt and Explorer from the Start menu if the computer is logged on by Guest.

Encryption

Word and other word processors offer a built-in system for encryption. You reach it under the Save as menu.

Summary

These kinds of security offer only a light protection. Confidential data should be saved on a network server or on removable media.

NT Advantages

NT has higher stability and security than Windows 3 or Windows 95. NT is more resistant to viruses; there are very few viruses that can harm NT.

NT Disadvantages

New hardware is required, new installation required, fewer available drivers than on Windows 95, some DOS programs may not work, some Win 32 programs may work on Win 95 but not on Win NT.

Windows networking

This is sometimes called the poor man’s network. To enable it, you open the Control panel and choose Network. You must have a network adapter installed.

After that installation, you right-click on a resource and choose Share. The shared resource will be displayed with a little hand underneath.

With this service, you can use Workgroups. That is a way to connect to other computers running NT, Windows 3.11 or Windows 95, not even needing a dedicated network server. In this service, it’s possible to share local directories or resources, such as printer, modem and CD drive, with others. This is suitable for small networks, with up to 5 or 10 computers. Larger networks usually have a Novell, NT or Unix server.

Further reading

To really learn NT, you may need one of the official NT training kits from Microsoft.