Windows 98 Professional Reference

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Windows 98 Configuration Files

• IO.SYS and MSDOS.SYS
• CONFIG.SYS
• AUTOEXEC.BAT
• WIN.INI and SYSTEM.INI
• Conclusion

W indows 98 relies on certain key files when it starts. These files affect the configuration and operating behavior of Windows 98, and you can make changes that directly change these values. Under Windows 98, the following are key startup configuration files:

• MSDOS.SYS
• IO.SYS
• CONFIG.SYS
• AUTOEXEC.BAT
• WIN.INI
• SYSTEM.INI

You can edit all of these files except for IO.SYS, which is included in the list because it plays a key role in startup configuration (as you will see). In this chapter, you learn about how these files work, when they are accessed, and what changes you can make to them. Any of the editable files can be edited with any text editor, such as Windows Notepad or the MS-DOS EDIT command.

IO.SYS and MSDOS.SYS

The IO.SYS and MSDOS.SYS files are the first files processed as Windows 98 boots. IO.SYS is a binary file that is not editable, but which sets certain parameters for the system. You can override the settings made by IO.SYS with countermanding settings in CONFIG.SYS. (These commands were set by CONFIG.SYS prior to Windows 95.) You may want to change the commands set by IO.SYS when running Windows 98 in command-prompt mode (via the Windows Startup menu) or the configuration of the DOS virtual machines within Windows 98.

The commands set by IO.SYS (some of them changeable by countermanding commands in CONFIG.SYS) are as follows:

• BUFFERS=x. This command sets aside a number of file buffers for improving disk access times for applications running from the command line environment that use MS-DOS calls for file access. The default value set in IO.SYS is 30; you can set a higher value in CONFIG.SYS.
• DOS=HIGH. By default IO.SYS executes this command. If you need DOS=LOW, set the command in CONFIG.SYS. By default, when DOS=HIGH the UMB value is automatically included if EMM386.EXE is also being loaded by CONFIG.SYS.
• FCBS=x. Creates File Control Blocks (FCBs) for older MS-DOS applications. The default value set by IO.SYS is 4; you can increase it in CONFIG.SYS if needed by an older application.
• FILES=x. By default IO.SYS sets this value to 60. This command sets aside a quantity of file buffers to use for opening files with MS-DOS system calls, and is not used by Win16 or Win32 applications. You can set a different value in CONFIG.SYS, but it must be greater than the default set by IO.SYS.
• HIMEM.SYS. This file initializes the High Memory Area (HMA) for DOS virtual machines. It is loaded by default in IO.SYS.
• IFSHLP.SYS. The Installable File System Helper program loads file system device drivers. Until IFSHLP.SYS is loaded by IO.SYS, only a minimal file system is available to the system.
• LASTDRIVE=x. Set by default to the letter z, this command sets aside space to be used for drive letter assignments.
• SHELL=COMMAND.COM. Set by default in IO.SYS, you can use different SHELL parameters within CONFIG.SYS if needed by some application.

• STACKS=x. Sets aside a number and size of stack frames for use with older applications. The default value is 9,256, which creates nine stack frames of 256 bytes each. You can set a higher value with an entry in CONFIG.SYS.

For more detail on setting CONFIG.SYS commands such as the preceding, see the following section, "CONFIG.SYS."

The MSDOS.SYS file is an editable text file that contains commands that control how Windows 98 starts. Table 32.1 details the possible MSDOS.SYS settings and their affects.

Table 32.1 Possible Settings for MSDOS.SYS

CONFIG.SYS

Windows 98 uses a file called IO.SYS for the purpose originally served by CONFIG.SYS, which is to load key device drivers and initialize the most basic parts of the operating system before the command environment is created. CONFIG.SYS still exists in Windows 98, however, for compatibility purposes with older applications. In fact, some older MS-DOS applications could refuse to run if they don't find a particular command present in the CONFIG.SYS file, regardless of whether or not the settings in IO.SYS would satisfy their needs. For most Windows 98 systems, no commands are needed in CONFIG.SYS; all its former purposes should be served by IO.SYS and drivers loaded directly by Windows 98.

When Windows 98 is installed on top of an MS-DOS/Windows 3.x system, the following lines in CONFIG.SYS are automatically deleted, if found:

• IFSHLP.SYS
• FASTOPEN.EXE
• SHARE.EXE or SHARE.COM

• SMARTDRV.SYS or SMARTDRV.EXE

In addition to the preceding, many other lines may be deleted if found, such as those required to support other operating systems, or those used by older applications that might conflict with the smooth operation of Windows 98.

Commands listed in CONFIG.SYS are loaded in the order in which they appear in the file. Table 32.2 details the commands possible in Windows 98's CONFIG.SYS file.

Table 32.2 Possible CONFIG.SYS Commands in Windows 98

By using the DEVICE= statement, you can choose to load the following device drivers in CONFIG.SYS if needed; they are still included with Windows 98 for compatibility purposes:

• DISPLAY.SYS
• EMM386.EXE
• HIMEM.SYS

• KEYBOARD.SYS

• CDROMDRV.SYS

You can also choose to load other device drivers that may be required and that you may have from other sources; the preceding list merely represents the CONFIG.SYS drivers included with Windows 98 for compatibility purposes.

AUTOEXEC.BAT

AUTOEXEC.BAT is an MS-DOS batch file executed automatically as Windows 98 boots. Included for compatibility with MS-DOS programs, it is not needed for most Windows 98 systems.

Under previous versions of MS-DOS and Windows 3.x, certain commands were commonly placed in AUTOEXEC.BAT for the startup environment. These settings are now made in IO.SYS and are not needed in AUTOEXEC.BAT, even for MS-DOS virtual machines; however, you can specify changes to modify most of these settings in AUTOEXEC.BAT if needed. The default settings provided by IO.SYS now include the following:

• SET PATH=C:\WINDOWS;C:\WINDOWS\COMMAND
• PROMPT=$p$g
• SET TMP=C:\WINDOWS\TEMP
• SET TEMP=C:\WINDOWS\TEMP

• SET COMPSPEC=C:\WINDOWS\COMMAND\COMMAND.COM

If you edit AUTOEXEC.BAT under Windows 98, you'll have to observe some precautions to avoid problems:

• Do not load any disk-caching software with the AUTOEXEC.BAT file, including SMARTDRV. This software will conflict with the built-in caching in Windows 98.
• Do not load any mouse drivers in AUTOEXEC.BAT because Windows 98 provides such support.
• If previous versions of Windows are in different directories on the system, make sure to avoid including them in any PATH commands.
• Make sure that C:\WINDOWS and C:\WINDOWS\COMMAND are included in any PATH commands you set.

• The networking drivers and devices are not yet initialized when AUTOEXEC.BAT processes, and so any commands dependent on the network will not work properly. Instead, if you need to execute commands at startup that are network dependent, create a separate batch file and place it in the Windows 98 Startup folder.

WIN.INI and SYSTEM.INI

WIN.INI is an initialization file originally used in the Windows 3.x family of products. Some Win16 applications may still rely on settings in this file, and may still make changes to this file to create the desired behavior under Windows 98. Because of this, WIN.INI is still included with Windows 98 and still functions, although some of the lines used under Windows 98 are removed during installation and instead now exist purely in the Registry.

When you make changes to Windows 98's configuration, those changes are automatically updated into the appropriate INI files (if they're supposed to be listed there). For instance, when you make desktop configuration changes, WIN.INI is updated by Windows 98.

Some common WIN.INI section headings are shown in Table 32.3.

Table 32.3 Common WIN.INI Section Headings

In addition to WIN.INI, there also exists a file called SYSTEM.INI that behaves similarly, but is oriented toward operating system settings rather than application and desktop settings under Windows. You will generally not need to make manual changes to SYSTEM.INI unless instructed by a support person from Microsoft or an applications vendor. However, a sample SYSTEM.INI is shown in Listing 32.1.

Listing 32.1  A Sample SYSTEM.INI

subtype=
type=4
keyboard.dll=
oemansi.bin=
[boot.description]
keyboard.typ=Standard 101/102-Key or Microsoft Natural Keyboard
aspect=100,96,96
display.drv=S3 Vision968 PCI
mouse.drv=Standard mouse
system.drv=Standard PC
[386Enh]
ebios=*ebios
device=*vshare
device=*dynapage
device=*vcd
device=*vpd
device=*int13
mouse=*vmouse, msmouse.vxd
woafont=dosapp.fon
PagingDrive=G:
device=*enable
keyboard=*vkd
[power.drv]
[drivers]
wavemapper=*.drv
MSACM.imaadpcm=*.acm
MSACM.msadpcm=*.acm
wave=mmsystem.dll
midi=mmsystem.dll
[iccvid.drv]
[mciseq.drv]
[mci]
cdaudio=mcicda.drv
sequencer=mciseq.drv
waveaudio=mciwave.drv
avivideo=mciavi.drv
videodisc=mcipionr.drv
vcr=mcivisca.drv
QTWVideo=C:\WIN95\SYSTEM\MCIQTW.DRV
MPEGVideo=mciqtz.drv
[NonWindowsApp]
TTInitialSizes=4 5 6 7 8 9 10 11 12 13 14 15 16 18 20 22
[vcache]
[NWNP32]
[MSNP32]
[display]
[drivers32]
msacm.msg711=msg711.acm
vidc.CVID=iccvid.dll
VIDC.IV31=ir32_32.dll
VIDC.IV32=ir32_32.dll
vidc.MSVC=msvidc32.dll
VIDC.MRLE=msrle32.dll
MSACM.MSNAUDIO=msnaudio.acm
VIDC.IV50=ir50_32.dll
msacm.lhacm=lhacm.acm
msacm.msg723=msg723.acm
vidc.M263=msh263.drv
vidc.M261=msh261.drv
msacm.l3acm=l3codeca.acm
VIDC.VDOM=vdowave.drv
VIDC.MPG4=msscmc32.dll
vidc.vivo=ivvideo.dll
msacm.vivog723=vivog723.acm
msacm.voxacm119=vdk32119.acm
VIDC.TR20=tr2032.dll
VIDC.UCOD=clrviddd.dll
msacm.l3codec
msacm.iac2=C:\WIN95\SYSTEM\IAC25_32.AX
VIDC.IV41=ir41_32.dll
VIDC.YVU9=iyvu9_32.dll
MSACM.imaadpcm=imaadp32.acm
MSACM.msadpcm=msadp32.acm
MSACM.msgsm610=msgsm32.acm
MSACM.trspch=tssoft32.acm
[Password Lists]
BRUCEH=C:\WIN95\BRUCEH.PWL
BRUCE=C:\WIN95\BRUCE.PWL
[boot]
system.drv=system.drv
drivers=mmsystem.dll
user.exe=user.exe
gdi.exe=gdi.exe
sound.drv=mmsound.drv
dibeng.drv=dibeng.dll
comm.drv=comm.drv
shell=Explorer.exe
keyboard.drv=keyboard.drv
fonts.fon=vgasys.fon
fixedfon.fon=vgafix.fon
oemfonts.fon=vgaoem.fon
386Grabber=vgafull.3gr
display.drv=pnpdrvr.drv
mouse.drv=mouse.drv
*DisplayFallback=0
[TTFontDimenCache]
0 4=2 4
0 5=3 5
0 6=4 6
0 7=4 7
0 8=5 8
0 9=5 9
0 10=6 10
0 11=7 11
0 12=7 12
0 13=8 13
0 14=8 14
0 15=9 15
0 16=10 16
0 18=11 18
0 20=12 20
0 22=13 22

Conclusion

This chapter described the key Windows 98 startup files MSDOS.SYS, IO.SYS, CONFIG.SYS, AUTOEXEC.BAT, WIN.INI, and SYSTEM.INI. These files still play a role in Windows 98, although most of Windows 98's configuration information resides in the Registry files USER.DAT and SYSTEM.DAT. (See Chapter 10, "Mastering the Windows 98 Registry," for a discussion of the Windows 98 Registry.)

For more information on the role of the Registry and the startup files in the boot process, see Chapter 36, "The Windows 98 Boot Process and Emergency Recovery."

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