Sams Teach Yourself MCSE Windows NT Server 4 in 14 Days
(Publisher: Macmillan Computer Publishing)
Author(s): David Schaer, et al
ISBN: 0672311283
Publication Date: 12/15/97

Installation Media Requirements You have only one option here, a SCSI CD-ROM. Because RISC machines boot off of firmware, only devices initialized by the system directly will be available to perform the installation.

Primary File System Requirements FAT is the only file system initialized by a RISC system’s firmware. The FAT partition must be at least 2MB in size. This gives the partition room to hold the OSLOADER.EXE, HAL.DLL, and any *.PAL (DEC Alpha-specific) files to continue initializing NT. RISC-based systems use the Arcinst.exe utility to create and format partitions which may be NTFS.

On RISC-based machines the system administrator can secure the FAT partition through the Secure System Partition command on the Partition menu of Disk Administrator. This security feature is unique to the RISC platform and should not mislead you into thinking that FAT offers any file-level security.

3.3. Planning for Multiple Operating Systems

You might need or want to boot into a different operating system to perform certain functions. The operating systems that you want available to boot into in addition to NT will normally be installed before installing NT. Usually you will want to install the operating systems in the order of DOS, Windows 95, then NT.

You can install your operating systems in any order. Just repair the NT installation to return to a multiboot environment.

Don’t confuse the concept of multiple operating systems with environment subsystems. Environment subsystems let NT emulate an operating system so that applications written for those systems can run unchanged under NT. Because not all applications will run properly under the operating system emulators, NT provides the capability of booting into other operating systems. Only one operating system can be active at a time.

You can select the default operating system to start at boot time through the Startup/Shutdown tab in the System Properties dialog box under Control Panel, as shown in Figure 3.2.

Figure 3.2.  Setting the default operating system.

You also can adjust the time allowed to select an operating system boot choice before the default is loaded. The default loads immediately if the time-out value is set to 0.

Because FAT is the only file system supported by DOS, Windows 95, OS/2, and NT, FAT must be the file system on the system partition on dual-boot systems. Other partitions that contain file systems or configurations unique to a particular operating system are available only when the supported operating system is active.

3.3.1. Coexistence with DOS

When DOS is installed on a computer, the boot sector is modified to call the DOS initialization files. When NT is installed to the same partition, the NT installation program copies the boot sector information to a file called BOOTSECT.DOS. The information is saved before NT overwrites the boot sector so that it is available to be called later.

The operating system that is selected and booted is the actual operating system. It is in no way different in function because the boot process began with the NT loader. The installation and configuration of common devices must be performed under each operating system.

If the BOOTSECT.DOS file ever is deleted or corrupted or the NT boot sector is accidentally overwritten, the NT boot sector can be replaced. To do this, you must inspect the NT boot sector through the emergency repair options. Boot from NT Server Setup Disk 1—the emergency repair disk is not bootable—and select the option to repair. Under the repair options, clear all options except to inspect the boot sector. Simply insert other required disks as prompted. This process repairs both the boot sector and creates the BOOTSECT.DOS file if required.

3.3.2. Coexistence with Windows 95

Dual booting between Windows 95 and Windows NT is supported in the same way as dual booting NT and DOS. If dual booting is already configured for DOS, boot into DOS and run the Windows 95 setup. You must take care to ensure that you do not accidentally install Windows 95 in the same directory as Windows NT; this would overwrite the NT system files.

You must configure devices and software once under each operating system. Be especially careful when changing network settings; changing the IP address under NT will have no effect on the IP address under Windows 95. The same is true of physical hardware configuration settings; if a network card is moved to a different IRQ the change must be adjusted under both operating systems.

The only file system fully supported between NT and Windows 95 is FAT. However, not all FAT is created equal. Systems installed with OEM versions of Windows 95 might come installed with partitions formatted with an incompatible version of FAT called FAT32. FAT32 partitions would be accessible only under Windows 95.

Windows 95 cannot understand partitions formatted with NTFS. Partitions created as volume or stripe sets under NT are not accessible under Windows 95 even if formatted as FAT. Disks that were mirrored under NT do not appear or function as mirrored sets under Windows 95.