Troubleshooting Windows 95 Using Safe Mode
This article was previously published under Q156126
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IMPORTANT: This article contains information about editing the registry.Before you edit the registry, you should first make a backup copy of theregistry files (System.dat and User.dat). Both are hidden files in theWindows folder.
Starting Windows 95 in Safe mode can help you resolve issues that occurwhen you start Windows 95 normally. These issues include (but are notlimited to):
- Setup hangs during the first reboot
- Error messages
- Loss of functionality
Starting Windows 95 in Safe mode bypasses the current real-modeconfiguration and loads a minimal protected-mode configuration, disablingWindows 95 device drivers and using the standard VGA display adapter.
If the issue does not occur in Safe mode, you may be experiencing aconflict with hardware settings, real-mode configuration issues,incompatibilities with legacy Windows programs or drivers, or registrydamage.
For a description of the events that occur when you boot Windows 95 inSafe mode, see the following article in the Microsoft Knowledge Base:
122051 How Windows 95 Performs a Safe Mode Start
PREPARING TO TROUBLESHOOT IN SAFE MODEThe procedures in the following sections describe steps to troubleshootconfigurations in which Safe mode resolves an issue with Windows 95. Manyof these troubleshooting steps require changes to system configurationfiles. These changes are not intended to be permanent; they should beused as techniques for isolating the conflict that resulted in an issuewith the normal configuration.
The examples in this article assume that Windows 95 has been installed inthe Windows folder on drive C. Adjust the syntax as required by yourconfiguration.
Before you begin making changes, you should create an Emergency Boot Disk(EBD) if you do not already have one. You can use the EBD to restart thecomputer and edit the configuration files if any changes you make causethe computer to hang.
To create an Emergency Boot Disk, follow these steps:
- In Control Panel, double-click Add/Remove Programs.
- Click the Startup Disk tab, and then click Create Disk.
Troubleshooting the Windows 95 configuration files may require that thefiles be edited. You can use the MS-DOS text editor or SystemConfiguration Editor to edit these files.
To use the MS-DOS text editor, type edit.comat a command prompt, and then choose the Open command on the File menu toopen the file you want.
To use System Configuration Editor, click the Start button, click Run,type sysedit in the Open box, and then clickOK. Click the file you want to edit on the Window menu.
TROUBLESHOOTINGThe Safe-mode troubleshooting steps are broken into the followingsections:
- Issues with the real-mode configuration
- Windows 95 command-line switches
- Windows configuration files and programs started automatically at startup
- Protected-mode device drivers
- Changing the video driver to the standard VGA display driver
- Registry damage
- If the problem persists
ISSUES WITH THE REAL-MODE CONFIGURATIONWindows 95 bypasses the Config.sys and Autoexec.bat files in Safe mode. Areal-mode device driver or terminate-and-stay-resident program (TSR)loading in one of these files may conflict with Windows 95, leading tothe issues you are experiencing during a normal boot. The following stepscan help you determine if this is the case.
Test the Real-Mode Configuration
- Restart the computer. When you see the "Starting Windows 95" message, press the F8 key, and then choose Command Prompt Only from the Startup menu.
NOTE: If the Windows 95 graphical user interface (GUI) loads, edit the Autoexec.bat file and remove or disable the "win" line.
- Start Windows 95 with a minimal set of Windows drivers by typing the following line:win /d:mNOTE: If networking components are required to start Windows 95, type the following line instead of the line above:win /d:n
If the issue persists, the contents of the Config.sys or Autoexec.batfile may be at fault. You have determined that a conflict exists with thereal-mode configuration, and you should perform a clean boot of the real-mode configuration.
Clean Real-Mode BootWindows 95 does not require a Config.sys or Autoexec.bat file. Thesefiles are necessary only for backward compatibility. If you do not needthese files, rename them and restart your computer. For example, renamethe Autoexec.bat file to Autoexec.bak, and rename the Config.sys file toConfig.bak.
If the Config.sys and Autoexec.bat files are required, perform a cleanboot of the real-mode configuration with the required drivers. To do so,follow these steps:
- Restart your computer. When you see the "Starting Windows 95" message, press the F8 key, and then choose Step-By-Step Confirmation from the Startup menu.
- Load the following items when prompted:
- Dblspace driver (if the hard disk is compressed).
- Do not process the Config.sys file.
- Dblbuff.sys (only if prompted).
- Do not process the Autoexec.bat file.
- Load the Windows 95 graphical user interface (GUI), choosing to load all Windows drivers.
WINDOWS 95 COMMAND-LINE SWITCHESStarting Windows 95 with command line switches is an effective method forisolating issues with your configuration. The switches should be used fortroubleshooting only; use the information to modify your existingconfiguration and eliminate the conflict.
- Follow the instructions for a clean real-mode boot in the "Clean Real- Mode Boot" section above, but do not load the Windows GUI.
- Start Windows 95 using the troubleshooting command-line switches by typing the following line:win /d:fsvx
Description of Command-Line Switches/D - Used for troubleshooting when Windows 95 does not start correctly.
F - Disables 32-bit disk access. This is equivalent to disabling the hard disk controller(s) in Device Manager.
S - Specifies that Windows 95 should not use ROM address space between F000:0000 and 1 MB for a break point.
V - Specifies that the ROM routine will handle interrupts from the hard disk controller. This is equivalent to the System.ini file setting of "VirtualHDIRQ=FALSE."
X - Excludes all of the adapter area from the range of memory that Windows 95 scans to find unused space. This is equivalent to the System.ini file setting of "EMMExclude=A000-FFFF." If this switch resolves the issue, you may have a conflict in the upper memory area (UMA) that requires an Exclude statement.
NOTE: Each of the System.ini file entries referenced above belongs in the[386Enh] section of the System.ini file.
WINDOWS CONFIGURATION FILES AND PROGRAMS STARTED AUTOMATICALLYWindows 95 includes several methods for loading programs automatically.Starting in Safe mode prevents any programs from being startedautomatically.
Windows 95 includes a Win.ini and System.ini file for backwardcompatibility with legacy programs and device drivers. Upgrading aprevious installation of Windows 3.x to Windows 95, as well as addingsoftware, can lead to conflicts within the Windows configuration files.
Determine If Issue Is Related to Program Starting at StartupLoad Windows 95 by booting to a command prompt and starting Windows 95 bytyping win, holding down the SHIFT key forthe duration of the boot. This prevents any programs from loadingautomatically at startup.
If the issue is resolved by preventing programs from loading at startup,investigate the following possible sources:
The Winstart.bat FileThe Winstart.bat file is used to load TSRs that are required for Windows-based programs and are not needed in MS-DOS sessions.
For more information concerning the Winstart.bat file, see the followingarticle in the Microsoft Knowledge Base:
134402 Some TSRs Moved from Autoexec.bat to Winstart.bat During Setup
The Win.ini FileThe "load=" and "run=" lines in the [Windows] section of the file canstart programs automatically. See the following section for moreinformation.
The Startup GroupIf the issue is resolved by bypassing the Startup group, remove each ofthe programs from the Startup group individually to isolate the problemprogram.
The Run Key in the RegistryWARNING: Using Registry Editor incorrectly can cause serious problemsthat may require you to reinstall Windows 95. Microsoft cannot guaranteethat problems resulting from the incorrect use of Registry Editor can besolved. Use Registry Editor at your own risk.
NOTE: For information about how to edit the registry, view the ChangingKeys And Values online Help topic in Registry Editor (Regedit.exe). Notethat you should make a backup copy of the registry files (System.dat andUser.dat) before you edit the registry.
You can prevent programs from loading by removing the program's stringfrom the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunPrograms may also being loading from the following registry key:
Test Windows Configuration FilesTo test the Windows configuration files, follow these steps:
- Boot to a command prompt.
- Rename the Win.ini file by typing the following line:ren c:\windows\win.ini *.bakStart Windows 95 by typing win. If this procedure corrects the problem, ensure that the "load=" and "run=" lines in the [Windows] section of the Win.ini file are either blank or preceded with a semicolon (;) to prevent the items from loading.
- Rename the System.ini file by typing the following line:ren c:\windows\system.ini *.bak
- Windows 95 requires a System.ini file to load the graphical user interface (GUI). Replace the original file by typing the following line:copy c:\windows\system.cb c:\windows\system.iniNOTE: Starting Windows 95 with the System.cb file does not load a driver for the mouse. Edit the new System.ini file, adding the following lines:
[386Enh] mouse=*vmouse, msmouse.vxd [boot] drivers=mmsystem.dll mouse.drv=mouse.drvStart Windows 95 by typing win at the command prompt. If replacing the original System.ini file with the System.cb file corrects the issue, the problem most likely resides with either the [boot] or [386Enh] sections of the original System.ini. Restore the original file to troubleshoot it.
To isolate the cause of the problem, place a semicolon (;) at the beginning of a line to prevent the item from loading.
140441 Creating a New System.ini File Without Third-Party Drivers
PROTECTED-MODE DEVICE DRIVERSSafe mode disables all protected-mode device drivers for Windows 95.Testing for incompatible components and resource conflicts can beconducted by disabling the protected-mode device drivers in DeviceManager.
Removing Protected-Mode Device Drivers to Isolate Conflicts
- In Control Panel, double-click System.
- Click the Device Manager tab, and click the View Devices By Type option.
- Disable each of the protected-mode device drivers. For example:
- Double-click the Floppy Disk Controllers branch to expand it.
- Click Standard Floppy Disk Controller, and then click Properties.
- On the General tab, click the Original Configuration (Current) check box to clear it, and then click OK.
NOTE: If you have enabled hardware profiles, there is a check box for each of the configurations. Clear the check box for the hardware profile you are troubleshooting.
If there is no Original Configuration (Current) check box, click the Disable in This Hardware Profile check box to select it.
NOTE: In Windows 95 OSR2, the user interface has changed. Click the Disable In This Hardware Profile check box to select it to disable a protected mode driver.
- Repeat steps A-C for each device in Device Manager.
- Click Close, and then restart the computer.
133240 Troubleshooting Device Conflicts with Device ManagerIf you determine that a Windows 95 protected-mode device driver isincompatible with your hardware, contact the hardware vendor to determinethe availability of new drivers.
CHANGING THE VIDEO DRIVER TO STANDARD VGA DISPLAY DRIVERNOTE: If you followed the directions in the previous section ("RemovingProtected-Mode Drivers to Isolate Conflicts"), you changed the displaydriver to VGA, and you can skip to the next section. Disabling thedisplay adapter sets your video to the VGA driver.
Safe mode starts Windows 95 with the VGA display driver. To determine ifthe issue you are experiencing is related to your video driver, change tothe VGA driver for testing purposes.
NOTE: To ensure a safe return to your previous configuration:
- Back up the System.ini file.
- Note the current desktop area (resolution) and color palette.
- Record the name of your current video adapter.
- Start Windows 95 in Safe mode.
- In Control Panel, double-click Display.
- On the Settings tab, click Change Display Type.
- In the Adapter Type area, click Change.
- Click the Show All Devices option.
- In the Manufacturers box, click (Standard Display Types). In the Models box, click Standard Display Adapter (VGA), and then click OK.
- Click OK or Close until you return to Control Panel. When you are prompted to restart your computer, do so.
REGISTRY DAMAGEWhen you start Windows 95 in Safe mode the registry is read minimally.Damage to the registry may not be evident when running in Safe mode; itmay be necessary to replace the existing registry (System.dat) with abackup to determine if the issue is caused by a damaged registry. Totroubleshoot a damaged registry, follow these steps:
- Boot to a command prompt.
- Type the following line to remove the file attributes from the backup of the registry:c:\windows\command\attrib -h -s -r c:\system.1st
- Remove the file attributes from the current registry by typing:c:\windows\command\attrib -h -s -r c:\windows\system.dat
- Rename the registry by typing:ren c:\windows\system.dat *.dax
- Copy the backup file to the current registry by typing:copy c:\system.1st c:\windows\system.dat
- Restart your computer.
NOTE: The System.1st file is a backup of the registry created during the final stage of Windows 95 Setup. Therefore, the "Running Windows 95 for the first time" banner is displayed and Windows 95 finalizes settings as if it were being installed.
If the issue is not resolved, restore the original registry. To do so,follow these steps:
- Restart the computer to a command prompt.
- Type the following lines:c:\windows\command\attrib -s -h -r c:\windows\system.dat
copy c:\windows\system.dax c:\windows\system.dat
- Restart the computer.
139437 Windows 95 Emergency Recovery Utility
135120 Configuration Backup Tool for Backing Up the Registry
IF THE PROBLEM PERSISTSIf the troubleshooting steps outlined in this article do not resolve theissue, the issue may be related to one or more of the following items:
- Faulty hardware
- The computer requires a special machine switch for HIMEM.SYS
- CMOS settings may need to be changed (such as disabling shadow RAM)
- The system ROM BIOS may require an upgrade to be compatible with Windows 95
- A virus
- An unsuccessful upgrade of a previous Windows installation
If you have enough free disk space, install Windows 95 to an empty folder(such as a Win95 folder). For information about how to do so, see thefollowing article in the Microsoft Knowledge Base:
142096 How to Reinstall Windows 95 to a New FolderIf this resolves the issue, your previous installation may have includedcomponents incompatible with Windows 95.Consult your computer's documentation or manufacturer for informationabout modifying the CMOS settings and the availability of BIOS upgrades.
Article ID: 156126 - Last Review: 12/04/2015 15:22:06 - Revision: 1.1
Microsoft Windows 95, Microsoft Windows 95
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