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Microsoft KB Archive/129260

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Windows 95 Setup: Description and Troubleshooting Steps


The information in this article applies to:

  • Microsoft Windows 95

This article describes troubleshooting steps that may help you solve problems installing Windows 95. This information is also available in our Windows 95 Setup Troubleshooting Wizard. We recommend using this wizard, but we have also created this text-based article for your convenience. The Windows 95 Setup Troubleshooting Wizard is located on:


This article lists steps to troubleshoot Setup problems and describes the Windows 95 Setup process for a typical upgrade from an earlier version of Windows.


Troubleshooting Setup

Before you try any of the following steps, create a boot disk for your current operating system. Copy any files you need to start your computer (including the Autoexec.bat and Config.sys files) to the boot disk. Make sure to include any necessary device driver files (such as a device driver that gives you access to the hard disk). For instructions about how to create a boot disk, please consult your operating system's documentation.

Clean Boot

If you have problems installing Windows 95, you should first try a clean boot. If no disk-compression software, disk partitioning software, or other third-party driver is necessary to start your computer, follow these steps to try a clean boot:

  1. Rename the Config.sys file to To do so, type the following line at a command prompt:

    ren c:\config.sys

  2. Rename the Autoexec.bat file to To do so, type the following line at a command prompt:

    ren c:\autoexec.bat

  3. Restart your computer and run Setup again.

Setup from MS-DOS:

If disk partitioning, disk compression, or other third-party software is required to start your computer, the Autoexec.bat and Config.sys files should appear as follows:

   <Third-party disk partitioner>
   <Third-party disk compression driver>
   <Other required third-party driver>
   shell=c:\<dir>\  /E:1024 /P

   prompt $p$g

Setup from Windows:

If disk partitioning, disk compression, or other third-party software is required to start your computer, the Autoexec.bat and Config.sys files should appear as follows:

   device=c:\<dir>\emm386.exe x=a000-f7ff nohi noems novcpi nomovexbda notr
   <Third-party disk partitioner>
   <Third-party disk compression driver>
   <Other third-party drivers>
   shell=c:\<dir>\  /E:1024 /P

   prompt $p$g
   set temp=c:\<dir> 

Close all running Windows-based programs (except Program Manager) and disable 32-bit file and disk access before you run Setup again.

NOTE: These examples assume you are not running Setup from a network. If you are running Setup from a network, please consult your network administrator for information about using a minimal boot.

ScanDisk Stops Responding (Hangs)

If your computer hangs while ScanDisk is checking the hard disk for problems, Setup should return control of the computer to you after three minutes of inactivity. If Setup does not return control to you, run ScanDisk from the command prompt, and then run Setup again. If Setup continues to hang, run Setup with the /IS switch to prevent ScanDisk from running. When you do this, Setup runs Chkdsk.exe to check for cross-linked files.

Setup Hangs

The most common causes for Setup to hang are viruses and anti-virus software. If Setup hangs, first run an anti-virus program. If no viruses are found, check to see if an anti-virus program is resident in memory.

Some computers include an anti-virus feature that prevents programs from writing to the boot sector of the hard disk. Such features may be set in your computer's CMOS settings. If anti-virus protection is running, Setup cannot finish the installation, or Windows 95 does not load properly.

To work around this problem, disable the anti-virus feature in your computer's CMOS settings and then run Setup again. Once you have successfully completed Setup you can re-enable the anti-virus feature. For information about how to change CMOS settings on your computer, please contact your computer manufacturer.

Setup may also hang if the full (OEM) version of Windows 95 is being installed onto a clean, bootable SCSI hard disk (for example, the boot disk that ships with the product is not used. Instead Io.sys, Msdos.sys, and are copied to the hard disk).

During Setup, SMARTDrive is automatically loaded but double-buffering is not enabled. If Windows 95 is being installed onto a SCSI hard disk that requires double-buffering, Setup may hang while temporary files are being copied to the hard disk.

To work around this problem, run Setup with the /C switch to prevent SMARTDrive from loading.

Setup Hangs on Disk 2

This problem can be caused by either of the following situations:

  • Change-line support is not working properly.

    If Setup cannot read disk 2 after it reads disk 1, try the following steps:

    1. Add the appropriate line to the Config.sys file:

      For a 1.44-MB drive A:

               drivparm=/d:0 /f:7 

      For a 1.44-MB drive B:

               drivparm=/d:1 /f:7 

      NOTE: Because the /C switch is not included in these lines, MS-DOS does not depend on change-line support. If the Config.sys file contains a Driver.sys line, disable it by placing the REM command at the beginning of the line.

    2. Restart the computer and then run Setup again.

      If Setup works correctly, change-line support is not functioning properly. Leave the Drivparm statement in the Config.sys file.

      If Setup still does not work correctly, remove the Drivparm statement from the Config.sys file and consult the computer's manufacturer to make sure that the computer's CMOS settings are correct.
  • You may have bad Setup disks.

    Disks 2-13 are Distribution Media Format (DMF) disks rather than standard MS-DOS-formatted disks. DMF disks can store more information than standard MS-DOS-formatted disks. However, some computers may have trouble reading DMF disks. If you have a computer that does not read DMF disks properly, Setup may not work properly.

    You can use the following steps to troubleshoot DMF disk issues:

    1. Copy the Extract.exe file from disk 1 to the root folder of drive C. To do so, type the following line at the command prompt:

      copy a:\extract.exe c:\

    2. Create a temporary folder on your hard disk by typing the following line at the command prompt:

      md c:\win95tmp

    3. With disk 2 in drive A, extract the and files to the folder you created in step 2. To do so, type the following commands:

      extract /e a:\ /l c:\win95tmp extract /e a:\ /l c:\win95tmp

      NOTE: You must use the Extract command with all disks (except disk 1) because they are DMF disks.

      For additional information about using the Extract command, please see the following article in the Microsoft Knowledge Base:

      Q129605 How to Extract Original Compressed Windows Files

    If you cannot extract these files from disk 2, try to extract a different .cab file from a different disk. If you cannot extract any .cab file, your computer hardware may not be functioning correctly, or your computer may be infected with a computer virus.

    You should run current virus detection software to determine if your computer is infected with a virus. If a virus is detected, remove the virus from the computer, and then try to extract the files again.

    NOTE: If a virus has infected a Setup disk, the disk cannot be used. You will need replacement disks.

    If you are still unable to extract the files after verifying that your computer is not infected with a virus, try extracting the files using another computer. If you are able to extract the files using another computer, you should contact your hardware manufacturer for assistance with properly configuring or replacing your malfunctioning computer hardware.

    If you encounter problems only when you try to extract certain .cab files but you can extract other .cab files, you may need replacement disks. Please call (800) 360-7561 or Microsoft Technical Support for replacement disks.

Setup Hangs During Hardware Detection

If Setup hangs while it is detecting hardware in your computer, try the following steps:

  1. Turn your computer off, wait a few seconds, then turn it back on.

NOTE: Do not use the reset button or press CTRL+ALT+DELETE to restart your computer.

  1. Run Setup again and choose Smart Recovery when you are prompted.

If Setup continues to hang at the same place during hardware detection, follow these steps:

  1. Run Setup.
  2. Click the Custom Setup option button when you are prompted.
  3. When you are prompted "Do you want Setup to look for all hardware devices?" click "No, I want to modify the hardware list."
  4. In the Hardware Types list, click only the following types:

          Floppy Disk Controller
          Hard Disk Controller
  5. If Setup continues to hang during hardware detection, run Setup again and select different combinations of hardware types. For example, select only Display, Floppy Disk Controller, Keyboard, and Mouse.

Setup Hangs While Creating the Startup Disk

Setup may hang or generate a general protection (GP) fault error message when it tries to create the Startup Disk. This problem may be due to the presence of a virtual device driver (VxD) from Norton Utilities. To work around this problem, use either of the following methods:

  • Start Setup again. When you are prompted whether you want to create a Startup Disk, click No.
  • Remove the "device=symevnt.386" line from the [386Enh] section of the System.ini file and then run Setup again. Use any text editor (such as Notepad or to edit the System.ini file and remove this line.

If you choose not to create a Startup Disk during Setup, you can create one after Setup is finished. To do so, follow these steps in Windows 95:

  1. Click the Start button, point to Settings, then click Control Panel.
  2. Double-click the Add/Remove Programs icon, then click the Startup Disk tab.
  3. Click the Create Disk button to create a Startup Disk.

Setup Hangs After the First Reboot

Setup may hang after the first reboot for one of the following reasons:

  • There is a video driver conflict, or an incompatible real-mode hard disk driver. Try to start Windows 95 in Safe Mode by following these steps:

    1. Restart Windows 95. Press the F8 key when you see the "Starting Windows 95" message.
    2. Choose Safe Mode from the Microsoft Windows 95 Startup menu.

    If Windows 95 starts, change the video driver to the standard VGA driver by following these steps:

    1. Click the Start button, point to Settings, then click Control Panel.
    2. Double-click the Display icon.
    3. Click the Settings tab, then click the Change Display Type button.
    4. Click the Change button in the Adapter Type section, then click the Show All Devices option button.
    5. Click "(Standard Display Types)" then double-click Standard Display Adapter (VGA). Click OK.
    6. Restart Windows 95 normally.

    For additional information about troubleshooting video problems in Windows 95, please see the following articles in the Microsoft Knowledge Base:

    Q127139 Troubleshooting Video Problems in Windows 95

  • There may be a damaged Windows 3.1 group (.grp) file. To correct this problem, turn your computer off, wait a few seconds, then turn it back on. Run the Group Converter tool (Grpconv.exe) to rebuild each .grp file individually.

"Incorrect System Disk" or "Invalid System Disk" Error Message

CAUTION: If you are using Disk Manager or any other disk drive overlay program on a hard disk, make sure that the overlay driver is loaded before you use the SYS command on that hard disk. If the overlay driver is not loaded and you use the SYS command on the hard disk, the drive may not be recognized as being partitioned by the disk drive overlay program and you could experience a data loss or inability to boot from the drive.

You can work around this problem by manually installing the Windows 95 system files on the hard disk. To do so, follow these steps:

  1. Start your computer with the Startup Disk created during Setup.
  2. Make a backup copy of the current Msdos.sys file by typing the following lines at the command prompt:

          attrib c:\msdos.sys -r -s -h
          ren c:\msdos.sys c:\ 
  3. Use the command from the Startup Disk to transfer the system files to the hard disk by typing the following lines at the command prompt:

          sys c: 
  4. Replace the new Msdos.sys file with the backup copy by typing the following lines at the command prompt:

          attrib c:\msdos.sys -r -s -h
          del c:\msdos.sys
          ren c:\ msdos.sys
          attrib c:\msdos.sys +r +s +h 

Setup Hangs on the Second Reboot

For information about troubleshooting this and other problems in Windows 95, please see the following article in the Microsoft Knowledge Base:

Q119941 How to Rebuild, Convert, Troubleshoot Folders in Windows 95

Starting Setup

Microsoft Windows 95 can upgrade Windows version 3.0 and higher and Windows for Workgroups version 3.1 and higher. If you are using Windows 3.0, you must run Setup from MS-DOS. If you are using Windows 3.1 or Windows for Workgroups 3.1 or higher, you can run Setup from MS-DOS or Windows.

Windows 95 can upgrade MS-DOS, PC-DOS, or OEM-DOS version 3.2 and higher.

Setup Step-by-Step

Understanding the steps that Setup performs may help you to troubleshoot problems you encounter during the Setup process. Setup performs the following steps:

Step 1 - Initializing Setup

In this step, Windows 95 prepares your computer for installation by performing the following functions:

  • If you run Setup from MS-DOS, Windows 95 searches the local hard disk for a previous version of Windows 3.1 or later. If a previous version is found, Setup recommends that you quit Setup and then run Setup again from inside the existing Windows version.
  • Setup checks for the minimum system configuration.
  • Setup checks for an extended memory manager (such as Himem.sys) and a disk cache program (such as Smartdrv.exe). If either is not found, Setup loads one.
  • Setup checks for the presence of "dirty" or "deadly" terminate-and- stay-resident programs (TSRs) that are known to cause problems with Windows 95 Setup. Use Setup /IT to ignore this TSR check.
  • If you run Setup from MS-DOS, Setup installs the necessary components for mini-Windows. Setup stores these files in a temporary directory it creates called Wininst0.400.
  • Setup runs Scandisk /ALL /NOTEXT to check the hard disk for any problems. Use Setup /IS to not run ScanDisk during Setup.
  • Setup starts the graphical user interface (GUI) and displays the "Welcome to Setup" message. At this point, Setup switches the processor into protected mode and makes extended memory available.
  • If Setup finds an OLD_DOS.X directory, it asks you if you want to delete this information to free hard disk space.

An OLD_DOS.X directory is created when you install the MS-DOS 6.x Upgrade or Step-Up. This directory is used if you decide to remove the upgrade and return to your earlier version of MS-DOS. If you did not install the MS-DOS 6.x Upgrade or Step-Up, you do not have an OLD_DOS.X directory.

Step 2 - Preparation for Smart Recovery

If for any reason Setup does not finish and the computer needs to be restarted, the following lines in the Autoexec.bat file prompt you to run Setup again and choose the Smart Recovery option:

   @if exist c:\wininst0.400\suwarn.bat call c:\wininst0.400\suwarn.bat
   @if exist c:\wininst0.400\suwarn.bat del c:\wininst0.400\suwarn.bat 

Step 3 - Read the Setuplog.txt File

Setup reads the Setuplog.txt file to see if Setup failed previously. If Setup did fail previously, Setup prompts you to run Smart Recovery or to continue using the Full Install option.

If the Setuplog.txt file is complete and you run Setup from the same version of Windows, Setup provides a Verify option. Using this option causes Setup to check the Windows 95 file sizes and dates. If a file is damaged, Setup re-installs it.

Step 4 - Gathering Information

Setup collects information from you (such as your name and the directory in which to install Windows 95) and writes that information to the Setuplog.txt file for use when copying files.

Step 5 - Hardware Detection

Hardware detection is the most intense portion of Setup. Windows 95 maintains a database of known legacy (non-Plug and Play) devices and the resources that they use. Setup polls all of these resources (I/O ports, IRQs, DMA channels, memory addresses, and so on) and looks for responses to determine what device is using each resource. If Setup detects a Plug and Play device, it adds that device's configuration information to the registry.

Setup creates the registry and puts the,, and Detlog.txt files in the root directory of drive C. To help speed the process of searching through the extensive .inf files, Setup uses two indexing files, Drvidx.bin and Drvdata.bin, from the temporary directory (Wininst0.400).

Step 6 - Windows Components

When you select the components to install (or accept the default components), Setup writes them to the Setuplog.txt file with the other Setup information.

Step 7 - Preparing to Copy Files

Setup uses the Setupx.dll file to create a list of files to copy based on the components you selected.

Step 8 - Copying Files

If you chose to create a Startup Disk, Setup copies the Startup Disk files now. Next, Setup copies the files prepared in step 7 to the hard disk.

Step 9 - Finishing Setup

After copying all the necessary files, Setup upgrades the existing copy of Windows and replaces the existing MS-DOS version with the Windows 95 operating system. After Setup reaches 100% complete, it writes information to the hard disk's master boot record (MBR) and renames the Io.sys and Msdos.sys files to Io.dos and Msdos.dos. At this point you are prompted to click the Finish button so that Setup can restart your computer and complete the installation.

Step 10 - Configuring Hardware

Setup updates the configuration files by running Winint.exe to process the options in the Wininit.ini file. The Wininit.ini file tells Setup to create the Vmm32.vxd file and to rename the files that were used by Setup initially but are no longer needed.

Step 11 - Run-Once

Setup runs the Run-Once module. This module is specified in the registry and installs certain device configurations and printers, converts .grp files to Windows 95 format, sets the time and date, and sets up the Help system for Windows 95.

Step 12 - Second Reboot

This step does not occur on all computers. Setup may restart your computer a second time so that it can finalize the hardware settings. This extra step lets Setup detect hardware that could not be detected during the original hardware detection.

For example, if your computer contains a sound card with a built-in SCSI controller, Setup detects the sound card and SCSI controller during the initial hardware detection phase. Setup restarts your computer a second time so that it can load the SCSI enumerator and detect whatever is attached to the SCSI controller (such as a CD-ROM drive).

Additional query words: w95setfaq

Keywords : kbsetup win95
Issue type :
Technology : kbWin95search kbWin95

Last Reviewed: March 29, 2001
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