Tech Tips / Windows NT / Startup and Shutdown
Boot.ini switches
An often-overlooked feature of Windows NT is using the Boot.ini file to help diagnose problems and configure other boot options. Let's examine some of the switches that can be added to the menu lines. Remember that Boot.ini is a read-only file, so remove the attribute before adding these switches. Editing can be done with Notepad.
- /3GB: Allows user-mode applications to access 3 GB of memory instead of the 2 GB that Windows NT normally allocates to user-mode applications. It moves the starting point of kernel memory to 3 GB. This switch is used only in the Windows NT Server Enterprise Edition of Windows NT with Service Pack 3.
- /BASEVIDEO: The /BASEVIDEO switch forces the system into standard 640x480 16-color VGA mode. This is used to allow the system to load if the wrong video resolution or refresh rate had been selected.
- /MAXMEM=nn: This switch selects the amount of memory Windows NT detects and can use at startup. This setting should never be less than 12. This option is good for checking for bad memory chips or testing performance with different amounts of RAM (e.g., /MAXMEM=32).
- /NOSERIALMICE:COMX: This switch disables the mouse port check for this com port (e.g., /NOSERIALMICE:COMX, where X is the number of the serial port). Ports may be separated with commas to disable more than one port. If no serial port is given, then ALL ports will be disabled for mouse devices. This is used with uninterruptible power supplies (UPSs), like those from American Power Conversion brand (APC) that connect to a serial port. If this option is not available when Windows NT starts and Windows NT tries to detect a mouse on this port, the UPS will accidentally start its shutdown mode.
- /SOS: The /SOS switch causes the loader to print the name of loaded modules. When Windows NT comes up, instead of displaying dots while the devices load, Windows NT will show the actual names of the drivers while they load.
- /WIN95: The /WIN95 switch loads Bootsec.dos.
- /WIN95DOS: The /Wind95DOS switch loads Bootsec.w40