The Msdos.sys file is located in the root of the system partition (Usually C:), and contains settings that control the startup of Windows 9x. The Msdos.sys is a standard text-file, which can be edited using Notepad.

The MsDos.sys contains two sections:

• [Paths] - Specifies the location of the Windows installation.
• [Options] - Specifies the settings used at Windows startup.

Some of the more useful settings available in the [options]-section:

Setting	Description
AutoScan = 2	Run scandisk at startup after Windows crash (0 = No, 1 = Prompt, 2 = Scan)
BootDelay = 0	How many seconds one have to press F5/F8 to break startup
BootGUI = 1	Launch Windows after running Autoexec.bat
BootKeys = 1	Enable startup keyboard keys (F5/F8)
BootMenu = 1	Show boot menu by default, like if the F8 key was pressed
BootMenuDelay = 3	How many seconds it should show the boot menu before continuing
BootMulti = 0	Allows booting to the previous operating system Windows by pressing F8 at startup
DblSpace = 0	Load double space drivers
DrvSpace = 0	Load drive space drivers
DoubleBuffer = 0	Enable double buffering for SCSI devices
Loadtop = 1	Load Command.com in upper memory
Logo = 1	Show Windows logo while booting
Network = 1	Enable network support in safemode

More Info MS KB118579