Windows 95 Setup Command Line Switches

When installing Windows 95 via MS-DOS or an existing Windows installation, the SETUP.EXE executable supported a wide array of command-line switches. These switches allowed system administrators, system builders, and advanced users to bypass hardware diagnostics, disable automated system checks, optimize installation speed, and deploy unattended setup scripts.

Diagnostic and ScanDisk Switches

Setup ran several automatic validation routines prior to file extraction, which could cause hangs on older or non-standard hardware. The following switches controlled or bypassed these checks:

  • /IS: Skips the automatic ScanDisk routine entirely. Useful if ScanDisk hangs or if disk integrity has already been verified.
  • /IQ: Skips ScanDisk check for cross-linked files when starting Setup from MS-DOS.
  • /IH: Runs ScanDisk in the foreground so diagnostic messages and disk errors are visible on screen.
  • /ID: Bypasses the minimum disk space check, allowing Setup to continue even if free storage reporting is inaccurate.
  • /IM: Bypasses the check for low conventional memory (less than 412 KB).
  • /IT: Skips the check for problematic or incompatible Terminate-and-Stay-Resident (TSR) programs running in memory.
  • /NR: Skips the check for existing registry files.

Automation and Scripting Switches

For mass rollouts and automated provisioning, administrators could pass configuration files and skip interactive prompts:

  • [filename].inf: Supplying a path to a custom configuration file (such as MSBATCH.INF) runs an automated, hands-off setup according to the directives specified in that script.
  • /IW: Bypasses the Microsoft License Agreement prompt (often used in conjunction with batch script installations).
  • /NF: Skips the prompt that prompts the user to create a Startup Disk (floppy boot disk).
  • /NOSTART: Copies the minimal set of files needed for the Windows environment to run Setup, then exits to DOS without launching the graphical installation wizard.

Hardware and Driver Detection Switches

Windows 95 introduced Plug and Play, but incompatible hardware could cause detection routines to freeze:

  • /IN: Runs Setup without launching the Network Setup module, preventing network card detection and protocol configuration.
  • /IL: Loads the Logitech mouse driver instead of the default Microsoft mouse driver during the DOS phase of Setup.
  • /PA: Forces Setup to use full hardware detection routines even if hardware configuration files already exist.
  • /PJ: Bypasses the Plug and Play BIOS detection routines.
  • /PI: Forces an interactive prompt before attempting detection of specific legacy hardware devices.

System and Performance Switches

These parameters changed how temporary installation files and existing configurations were managed:

  • /C: Disables the loading of the SmartDrive disk-caching utility during Setup.
  • /D: Ignores the existing Windows installation and forces Setup to install a clean configuration rather than performing an upgrade.
  • /T:[path]: Specifies an alternate directory or drive for Setup to place temporary files during the installation process (e.g., SETUP /T:D:\TEMP).