First post, by GL1zdA

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Can anyone explain to me, why Windows 95 always adds the SET BLASTER value to the MS-DOS mode configuration in .PIF files, even if I don't specify it? I know Creative drivers will add SET BLASTER to AUTOEXEC.BAT automatically, but I'm curious what adds it to the ".PIF" files. Basically whenever I have defined something like 'SET BLASTER=A220 I5 D1 H5 P300 T6' in my environment, it will be added to the PIF, even if I don't set it myself. Are the Creative drivers that aggressive with their modifications or is it a Windows 95 feature I can't find any documentation for?

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Reply 1 of 2, by doshea

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GL1zdA wrote on 2021-05-15, 23:30:

is it a Windows 95 feature I can't find any documentation for?

Probably, I didn't know about it for a long time either! This doesn't seem to be documented on various contemporary MSDN or Technet CDs I checked, only in the OEM Preinstallation Kit (OPK) User's Guide in the "MS-DOS Utilization" chapter:

MS-DOS Mode Configuration Options 

An individual MS-DOS window can be configured to run in MS-DOS mode by starting
an MS-DOS Prompt as a window, right-clicking the MS-DOS icon in the MS-DOS
Prompt title bar, clicking Properties, and then clicking the Advanced button.
When the end user selects the MS-DOS Mode and the Specify A New MS-DOS
Configuration check boxes, he or she can change the configuration of the
CONFIG.SYS and AUTOEXEC.BAT files that will be loaded when the real-mode MS-DOS
runs. In addition, the end user can click the Configuration button, and a
Configuration wizard displays a set of options that will automatically
reconfigure AUTOEXEC.BAT and CONFIG.SYS.

The list of MS-DOS mode options presented in the Configuration dialog box in the
Select MS-DOS Configuration Options dialog box is completely configurable by
modifying entries in the system registry. Many options are considered
‘‘standard’’ and have a unique identifier bit that allows the Configuration
wizard to automatically create the appropriate entries in the shortcut’s

All entries are stored under the registry branch:


Each subkey in this registry branch describes a unique option. OEMs can add any
number of options. The key names are generally a unique English description of
the option, such as ‘‘EMS.’’ The value of the key is a language-specific
description of the option that will appear in the list box, such as ‘‘Expanded
Memory (EMS).’’

Under each option key there are several values used by the Configuration wizard
that determine which options should be used and which should be presented to the
end user. The following table describes these keys.

Option Data Description
(Default) String Language-specific description of
the option.
Flags Binary Dword bit field of options listed
Dword in the following table.
Order Binary Unsigned dword field used to sort
Dword options when the Configuration
wizard inserts the lines in
StdOption Binary For standard options, this dword
(optional) Dword specifies the bit mask for the
current option.
TipText String Language-specific text to be
(optional) displayed by the Configuration
wizard when the user clicks the
option in the Configuration dialog
Autoexec.Bat String Specifies a line to add to
(optional) AUTOEXEC.BAT if the option is
Config.Sys String Specifies a line to add to
(optional) CONFIG.SYS if the option is
Autoexec.Bat1 String If the DOSOPTF_MULTIPLE flag is set
to in the Flags value, these entries
AutoExec.Bat9 will be added to AUTOEXEC.BAT in
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                        addition to the ‘‘Autoexec.Bat’’ 
Config.Sys1 String If the DOSOPTF_MULTIPLE flag is set
to in the Flags value, these entries
Config.Sys9 will be added to CONFIG.SYS in
addition to the ‘‘Config.Sys’’

The following table describes the flags and the values for those flags used by
the options in the previous table.

Flag #define Value Description
DOSOPTF_DEFAULT 0x00000001 This option will be selected by
default in the Configuration
wizard’s list box.
DOSOPTF_SUPPORTED 0x00000002 This bit must be set or else the
option will be considered ‘‘not
supported.’’ Entries are always
made for all standard options by
Windows 95 Setup even if Setup
can not determine how to support
the option.
DOSOPTF_ALWAYSUSE 0x00000004 If this flag is set, the option
will never be presented as a
choice to the user (they won’t
see it in the Configuration
wizard’s list box) and the
entries will always be added to
the configuration.
DOSOPTF_USESPMODE 0x00000008 This flag should be set for any
entry that sets the computer
into protected mode. Generally,
this is only set for EMS
providers such as EMM386.
DOSOPTF_PROVIDESUMB 0x00000010 This flag should be set for any
entry that provides UMBs that
can be used by MS-DOS. All
entries that appear with an
order greater than this entry
and have a DeviceHigh or
LoadHigh specified in the entry
will be loaded high.
DOSOPTF_NEEDSETUP 0x00000020 Used only for the mouse on
upgrade installations. This
forces the Configuration wizard
to search the hard disk for a
mouse driver the first time it
is used.
DOSOPTF_INDOSSTART 0x00000040 The current option is supported
by an entry in DOSSTART.BAT.
DOSOPTF_MULTIPLE 0x00000080 The option has multiple

Maybe if you check that registry key you'll find the SET BLASTER there?

Reply 2 of 2, by GL1zdA

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These options in the registry are what appears in the box when you click "Configuration" in the "Advanced Program Settings". As for my original post, I found out, that Windows will update the PIF files with environmental variables when you leave the single application mode. That was the reason the PIF files were changed.

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