CONFIG.SYS and AUTOEXEC.BAT

For Windows 95, both the content and method have changed for handling CONFIG.SYS and AUTOEXEC.BAT during system startup. Windows 95 automatically loads drivers and sets defaults by using IO.SYS, the Registry, and other mechanisms, rather than CONFIG.SYS and AUTOEXEC.BAT.

However, computers that require certain real-mode drivers or TSRs will continue to require that software be loaded from these configuration files. Also, CONFIG.SYS and AUTOEXEC.BAT might be required to enable certain software options. However, some options, such as long command lines, can also be enabled by using the COMMAND.COM program properties, as shown in the following illustration.

CONFIG.SYS Processing

CONFIG.SYS defaults are implemented by IO.SYS, as described in the previous section. However, CONFIG.SYS can contain application-specific entries in addition to information stored in IO.SYS. These are processed in the sequence they are listed. After the base CONFIG.SYS file has been read, all devices are loaded, and COMMAND.COM is running.

Windows 95 loads memory managers supplied by other vendors if they are present in CONFIG.SYS; however, some might cause errors. Similarly, Windows 95 allows the use of command shells from other vendors, but, for example, long filenames are disabled, which might also indicate that other problems can occur using these command shells.

CONFIG.SYS Changes for Windows 95

Windows 95 has predefined settings built in for most common CONFIG.SYS settings, so Windows 95 Setup removes many of these lines (such as settings for files, buffers, and stacks) if they are equivalent to the default values, by using REM to comment out the line.

Tips for Editing CONFIG.SYS

If you edit CONFIG.SYS in Windows 95, observe the following basic guidelines:

• Do not include the smartdrv command. Windows 95 includes built-in disk-caching, and double-buffering is now provided by DBLBUFF.SYS.
• Remove any device=mouse.sys lines or similar lines. Windows 95 includes built-in mouse support.

The following tables describe the changes that Setup makes to CONFIG.SYS.

Device Entries Deleted from CONFIG.SYS if Found

Lines Removed from CONFIG.SYS for Non – MS-DOS Operating Systems

Miscellaneous Lines Removed from CONFIG.SYS

Lines Removed from CONFIG.SYS That Start Disk Caches

Lines Removed from CONFIG.SYS for Previous Versions of OEM-DOS

AUTOEXEC.BAT Processing

AUTOEXEC.BAT is not required for Windows 95, but it is included for compatibility purposes. If the computer has an AUTOEXEC.BAT file, each line is processed in sequence during system startup. AUTOEXEC.BAT can contain additional application-specific entries that are run in the sequence they are listed.

Windows 95 passes the initial environment to COMMAND.COM with the correct Windows and Windows COMMAND directories already in the path and with the environment variables PROMPT, TMP, and TEMP already set. (TEMP= and TMP= indicate locations for temporary directories; both are specified for compatibility reasons.)

The following AUTOEXEC.BAT commands have equivalent default settings created in IO.SYS for Windows 95.

AUTOEXEC.BAT Equivalents for Windows 95 IO.SYS Default Settings

The default Windows 95 environment includes the following:

tmp=c:\windows\temp
temp=c:\windows\temp
prompt=$p$g
path=c:\windows;c:\windows\command
comspec=c:\windows\command\command.com

AUTOEXEC.BAT Changes for Windows 95

Windows 95 Setup makes the following basic changes to AUTOEXEC.BAT:

• Updates the path= line statement
• Uses rem to comment out incompatible TSRs
• Deletes any win statement (or equivalent) and SHARE.EXE
• Copies the original AUTOEXEC.BAT to AUTOEXEC.DOS
• Sets the TEMP directory

For diskless workstations, if the TEMP and TMP environment variables are not set, Windows 95 Setup creates a TEMP directory in the home directory (which can be on the local hard disk or on the network), and adds set tmp= and set temp= entries in AUTOEXEC.BAT that point to the new directory.

Tips for Editing AUTOEXEC.BAT in Windows 95

If you edit AUTOEXEC.BAT, observe the following basic guidelines:

• Do not include other versions of Windows in your path.
• Start the path with C:\WINDOWS;C:\WINDOWS\COMMAND (using the name for the Windows 95 directory on your hard disk if it is not WINDOWS).
• Windows 95 Setup leaves your previous MS-DOS directory in the path. Do not change this.
• Do not add SMARTDrive or other disk caches. Windows 95 includes built-in caching.
• Do not include any statements for loading mouse support software. Windows 95 includes built-in mouse support.
• If it is necessary to connect to a network server when you start Windows 95, create a batch file, and run it from the STARTUP directory, rather than placing an entry in AUTOEXEC.BAT.

The following tables describe changes that Setup makes to AUTOEXEC.BAT. For entries that are removed, Setup uses rem to comment out the line.

Commands Removed from AUTOEXEC.BAT

Commands Removed from AUTOEXEC.BAT for Non – MS-DOS Operating Systems

Miscellaneous Lines Removed from AUTOEXEC.BAT

Lines Removed from AUTOEXEC.BAT That Start Disk Caches