Boot.ini Options

TABLE 1: Boot.ini Options
Option	Effect

/MAXMEM=	Limits NT to using only the amount of memory (MB) you specify (e.g., /MAXMEM=16 limits NT to using 16MB of the system's memory).
/BURNMEMORY=	Causes NT to discard as unusable the amount of memory (MB) you specify; limits memory as /MAXMEM does (e.g., /BURNMEMORY=128 causes NT to discard 128MB of the physical memory on the machine as unusable).
/ONECPU	Causes NT to enable only one CPU of a multiprocessor system.
/NUMPROC=	Enables only the number of CPUs you specify (e.g., /NUMPROC=2 on a 4-way system causes NT not to use two of the four processors).
/SOS	Causes NT to print information about what drivers load as the system boots.
/BASEVIDEO	Causes NT to use the standard VGA display driver when moving to GUI mode.
/NODEBUG	Prevents kernel-mode debugging from initializing. Overrides the specification of any of the three debug-related switches: /DEBUG, /DEBUGPORT, and /BAUDRATE.
/CRASHDEBUG	Has the same effect as /NODEBUG, although its name implies otherwise.
/DEBUG	Enables kernel-mode debugging.
/DEBUGPORT=	Enables kernel-mode debugging and specifies an override for the default serial port (COM1) a remote debugee connects to (e.g., /DEBUGPORT=COM2).
/BAUDRATE=	Enables kernel-mode debugging and specifies an override for the default baud rate (19200) a remote debugee will connect at (e.g., /BAUDRATE=115200).
/KERNEL=	Specifies overrides of NTLDR's selection of ntoskrnl.exe in the system root (<winnt>\system32) as the Kernel's
/HAL=	image file and of hal.dll as the HAL image file. Both options are useful for alternating between a checked Kernel environment and a free Kernel environment. If you want to boot into a checked environment that consists solely of the checked Kernel and HAL (typically all you need to test drivers), follow these steps on a system installed with the free build (retail NT):
		1.	Copy the checked version of the Kernel from the checked build distribution CD-ROM to your <winnt>\system32 directory, naming it ntoskchk.exe. If you are on a uniprocessor, copy ntoskrnl.exe; otherwise, copy ntkrnlmp.exe.
		2.	Copy the checked version of the HAL from the checked build distribution CD-ROM to your <winnt>\system32 directory, naming it halchk.dll. To determine which HAL to copy, go into your <winnt>\repair directory and open setup.log in Notepad. Search for hal.dll, and you'll find a line similar to "\WINNTF\system32\hal.dll = "halmps.dll","1a01c". The name to the right of the equal sign is the name of the HAL you need to copy.
		3.	Copy the default line in the system's boot.ini file.
		4.	In the string description of the boot selection, add something to identify that the new selection will be for a checked build environment (e.g., "Windows NT Server Version 4.0 CHECKED").
		5.	Add the following to the end of the new selection's line:
	/KERNEL=NTOSKCHK.EXE /HAL=HALCHK.DLL
Now you can select the new line to boot into a checked environment or select the pre-existing selection to boot into the free build.
/3GB	Causes the split between the user and system portions of NT's virtual address map to move from 2GB (2GB user, 2GB system) to 3GB (3GB user, 1GB system). This switch made its debut in NT 4.0 Service Pack 3 (SP3), and NT supports the switch in all subsequent releases. Giving virtual memory-intensive applications such as database servers a larger address space can improve their performance. However, for an application to take advantage of this feature, two conditions must hold: The system must be part of the NT Enterprise suite (SP3 is not), and the application must be flagged as 3GB-aware.
/PCILOCK	Stops NT from dynamically assigning I/O and IRQ resources to PCI devices and leaves the devices configured by the BIOS.
/NOSERIALMICE=	Disables serial mouse detection of the specified COM ports. Use this switch if you have a component other than a
[COMx \| COMx,y,z, ...]	mouse attached to a serial port during the startup sequence. If you use /NOSERIALMICE without specifying a COM port, NT disables serial mouse detection on all COM ports.