A Hidden Windows Configuration File
The core (or kernel) of the DOS operating system consisted of three files. These files are IO.SYS which contained the extensions to the BIOS required by DOS, MSDOS.SYS which contained the DOS loader, and COMMAND.COM which contained the base commands built into the Operating System. The first two of these three files has the hidden attribute set on by default.
With Windows 95 the functionality of the IO.SYS and MSDOS.SYS files were combined into the IO.SYS file making the MSDOS.SYS file available to be used for something else.
The something else that Microsoft decided to use the file for is as a file containing some very basic configuration options that they wanted to keep well hidden from Windows users.
This file is broken up into three parts. The first part starts with a line that reads [Paths] and contains information about where the operating system is installed. The second part starts with a line that reads [Options] and contains some options that control the way that Windows works. Finally, there is a long section of comments labelled Do not remove that is there to make sure that the length of the file is above 1024 bytes. This last section is required because the previous use of the file as a DOS loader was this size and some code within the operating system still hasn't been amended to reflect the change in the use to which this file is being put.
There are three statements that you will find in this section. They are:
- WinDir= which identifies the directory where windows has been installed.
- WinBootDir= which identifies where the windows boot files (himem and any drive compression driver) have been installed. This will be the same as the previous parameter location unless windows has been installed to a compressed drive.
- HostWinBootDrv= which identifies the drive letter of the drive on which the operating system was installed.
There are a lot more option parameters than there are path parameters and you will not necessarily find all of the following listed in your file.
- BootMulti= can be set to 0 or 1 with 0 being the default. If set to 1 then the option to boot to the operating system installed prior to the installation of Windows will appear in the boot menu. A value of 0 will remove the option from the boot menu.
- BootGUI= can be set to 0 or 1 with 1 being the default. If set to 1 then windows will boot to the graphical interface. When set to 0 it will boot to a DOS command prompt.
- AutoScan= can be set to 0, 1, or 2 with 1 being the default. This parameter controls when Scandisk will be run on startup with 0 indicating never, 1 indicating that it will run following an improper shutdown, and 2 indicating that it will always run.
- BootMenu= can be set to 0 or 1 with 0 being the default. A value of 1 means that the Boot Menu will always display when the system boots while a value of 0 means that it will only display if the F8 key is pressed.
- BootKeys= can be set to 0 or 1 with 1 being the default. A value of 0 disables the F4, F5, F8, Shift-F5, Ctrl-F5, and Shift-F8 function keys during system boot.
- BootDelay= indicates the number of seconds (default is 5) during which the system waits to see if a function key is pressed during the system boot.
- BootMenuDefault= sets the default entry within the boot menu. If not specified then the first entry in the menu will be the default.
- BootMenuDelay= sets the number of seconds (default 30) for which the boot menu will display before the default entry is automatically selected.
- Logo= can be set to 0 or 1 with 1 being the default. If set to 0 then the Windows logo will not be displayed during the system boot.
- WinVer= was introduced in Windows 98 to identify the version of Windows being run. A value of 4.10.1998 identifies Windows 98 and a value of 4.10.2222 identifies Windows 98SE. I have not yet had the opportunity to check out the value that this field contains on Windows ME.
There are a number of other parameters that can be entered in this section of the file but in customising your system, the ones listed are the ones I would think you would be most likely to be interested in.
This article written by Stephen Chapman, Felgall Pty Ltd.