NTLDR
NT loader, NTLDR short, the boot manager from Microsoft for all Windows NT systems up to and including Windows Server 2003. Its configuration it reads from the text file " boot.ini ". It is necessary because the Windows registry database is available only after the operating system starts. It also allows you to edit and outside of Windows. NTLDR was replaced by the bootmgr from Windows Vista.
Purpose and function
The configuration file is located next to the files " ntldr " and " ntdetect.com " and possibly " NTBOOTDD.SYS " and " bootsect.dos " in the root directory of the active primary partition (usually " C: \" ) and differs in the possible parameters depending version of Windows. This boot manager is necessary because Windows NT does not have a DOS core more and must be created before Windows launches an opportunity to influence the starting behavior of parameters. Since the DOS - based and Windows NT systems are functionally very different, should also in this way to create the possibility to operate several Windows versions in parallel.
An early very common dual boot scenario is the classic parallel operation of Windows 95 or Windows 98 and Windows NT 4.0. As this operating system had little multimedia support and does not support Plug and Play, and therefore also USB and FireWire were never implemented, it made sense to use for the daily work of stability because Windows NT, start to scan or for multimedia applications Windows 95 or 98.
The NTLDR is only used on x86 -based computers. RISC-based computers have a firmware that implements a boot menu, allowing to boot multiple operating systems. The file " osloader.exe " that exists only on RISC -based computers, the operating system starts directly using parameters that are passed to it by the firmware.
Structure of the boot.ini
The " boot.ini " is the configuration file of the boot manager " ntldr ". This file is necessary because the Windows registry database is available only after the operating system starts. The path is specified in the boot.ini conform to the conventions of RISC computers, which are defined in the ARC standard.
Example Configuration
[boot loader] timeout = 30 default = multi (0 ) disk ( 0) rdisk (0 ) partition ( 1) \ WINNT [operating systems ] multi (0 ) disk ( 0) rdisk (0 ) partition ( 1) \ WINNT = " Windows NT Workstation version 4.0" multi (0 ) disk ( 0) rdisk (0 ) partition ( 1) \ WINNT = " Windows NT Workstation Version 4.0 [ VGA mode ] " / basevideo / sos C: \ = "MS - DOS" C: \ bootsect.deb = " Ubuntu " [boot loader] initiates the configuration file timeout = xx indicates the time in seconds that the system waits until the default operating system starts, if there are multiple entries (default: 30) default = xx specifies the default operating system that is to be started [operating systems ] From here the individual entries of the operating systems are listed, it may more of the following entries are listed; with only one entry, the boot menu is not displayed when the computer starts; Windows 2000 is created in a default installation without further recognized operating systems into a single system entry. multi (0 ) disk ( 0) rdisk (1 ) partition ( 1) \ Windows directory = " text in the boot menu " [options ... ] starts a Windows installation from the System BIOS ( INT 13) scsi ( c ) disk ( d) rdisk ( l ) partition ( p) \ Windows directory = " text in the boot menu " [options ... ] starts a Windows installation on an explicit driver signature ( c ) disk ( d) rdisk ( l ) partition ( p) \ Windows directory = " text in the boot menu " [options ... ] starts a Windows installation on an explicit driver C: \ = "MS - DOS" provides a system startup regardless of the " ntldr " (here: System transfer to the DOS boot files on their stored as " bootsect.dos " next to the " boot.ini " boot sector ) and, as a rule only for DOS, DOS -based Windows systems not Microsoft systems comes into question C: \ bootsect.deb = " Ubuntu " provides a system startup regardless of the " ntldr " (here: system stored handover to the startup files on a Linux thereof as " bootsect.deb " next to the " boot.ini " boot sector ) Explanation of example: the Windows NT Start ( startup directory behind the partition information ) takes over the boot loader to load the startup files and drivers directly, for a DOS or DOS - based Windows passes the bootloader this work to the DOS startup files to which the following entry points. But the partition can be only one DOS and NT system start, foreign operating systems such as Linux and Netware are not officially supported. Also installing multiple Windows NT systems or more 3.x/9x-Versionen requires on the same machine a deeper knowledge of the behavior and the technical requirements of the various Windows versions and is not possible without manual intervention.
NTLDR boot from hard drive or disk without the master boot record to change, unlike some other boot loaders such as Linux. More advanced configurations can be better and more convenient ( or even only ) done with boot managers of other manufacturers and partitioning programs. A complete replacement for NTLDR, they are not, because it is integrated to load the startup files firmly into the NT system. It is compatible with most boot manager (eg GRUB and LILO for Linux) usually handle a parallel operation possible.
Locate the boot partition
Start with the system BIOS (INT 13)
Multi (0 ) disk ( 0) rdisk ( d ) partition ( p) \ Windows directory = " text in the boot menu " [options ... ]
D is the logical number of the disk from the BIOS perspective. 0 for the first plate ( 0x80), 1 for the second plate ( 0x81 ) etc.. This has nothing to do with master, slave or SCSI ID. When 3 is usually final.
P is the number of the partition on the disk. The first primary partition is 1 Then all other primary partitions followed by the extended follow. The extension itself partitions (type 0x05 and 0x0F ) do not count.
Windows directory is the % SystemRoot % of the relevant installation with no drive letter.
Options, see below.
Start with an explicit driver
Scsi ( c ) disk ( d) rdisk ( l ) partition ( p) \ Windows directory = " text in the boot menu " [options ... ]
For this variant, the file " NTBOOTDD.SYS " must be located in the root directory of the boot partition - ie where the " boot.ini " is. This file must be a (renamed) copy of the required response to the desired hard disk driver from % SystemRoot % \ System32 \ Drivers \. For IDE disks, which is usually " atapi.sys ", unless the used controller requires a vendor-specific driver ( SCSI always).