Topic summary
NTLDR
NTLDR (abbreviation of NTloader) is the boot loader for all releases of Windows NT from 1993 with the release of Windows NT 3.1 up until Windows XP and Windows Server 2003. From Windows Vista onwards it is replaced by Windows Boot Manager (BOOTMGR).
NTLDR is typically run from the primary storage device, but it can also run from portable storage devices such as a CD-ROM, USB flash drive, or floppy disk. NTLDR can also load a non NT-based operating system given the appropriate boot sector in a file.
NTLDR requires, at a minimum, the following three (or four) files to be on the system volume:
- ntldr, the main boot loader itself
- NTDETECT.COM, required for booting an NT-based OS, detects basic hardware information needed for successful boot
- boot.ini, which contains boot configuration
- If this file was missing, then it would default to the Windows directory on the first partition of the first hard drive (which by default is WINNT on most Windows NT releases until Windows 2000, WINNT35 on Windows NT 3.5 and 3.51, or WINDOWS on Windows XP and Windows Server 2003).
- Non-English versions of Windows may also load bootfont.bin.
NTLDR is launched by the volume boot record of system partition, which is typically written to the disk by the Windows FORMAT or SYS command.