Troubleshooting Windows 95 Startup Problems and Error Messages

This article lists troubleshooting tips you can use if your computer stops responding (hangs) or returns an error message (such as a fatal exception error or an invalid VxD error).

This article is meant to provide you with a general strategy for isolating the problem.

Safe Mode

If Windows 95 does not start, try to start it in Safe mode. To start Windows 95 in Safe mode, press the F8 key when you see the "Starting Windows 95" message, and then choose Safe Mode from the Startup menu.

If Windows 95 does not start in Safe mode, see the "Windows 95 Does Not Start in Safe Mode" section below. If Windows 95 starts in Safe mode, see the "Windows 95 Starts in Safe Mode" section below.

Windows 95 Does Not Start in Safe Mode

Any of the following conditions can cause Windows 95 not to start in Safe mode:

• Your computer is infected with a virus. For additional information about computer viruses, please see the following article in the Microsoft Knowledge Base:
  129972

  (http://support.microsoft.com/kb/129972/EN-US/ )

  Description of Computer Viruses

• Your computer's CMOS settings are not correct. Check your computer's CMOS settings to make sure they are correct. (You may need to contact the computer manufacturer to verify these settings.)

• There is a hardware conflict. These conflicts can include, but are not limited to, PCI BIOS settings, IRQ conflicts, redundant COM ports (for example, two COM1 ports, or an internal modem set to the same COM port as an existing serial port), and defective RAM chips.
• A setting in the Msdos.sys file needs to be changed (for example, the Logo setting should be set to zero). For additional information on the Msdos.sys file, please see the following article(s) in the Microsoft Knowledge Base:
  118579

  (http://support.microsoft.com/kb/118579/EN-US/ )

  Contents of the Windows Msdos.sys File
• You need to use the Vga.drv or Vga.vxd video drivers from the Windows 95 CD-ROM. These files are located in the Drivers\Display\Vga folder. For example, these drivers may be helpful if you have an Intel Triton PCI controller or a Cirrus Logic 5401 or 5402 VGA video adapter. For more information about these files, please see the Readme.txt file in the same folder.
• You are using Windows 95 OEM Service Release 2 (OSR2) and your computer stops responding (hangs) after booting to a previous operating system. For information about this issue, see the following article in the Microsoft Knowledge Base:
  155364

  (http://support.microsoft.com/kb/155364/EN-US/ )

  OSR2 Hangs After Booting Previous Operating System

If you still cannot start your computer in Safe mode after checking these items, reinstall Windows 95 in a new, empty folder. This step helps to establish whether the problem is related to a remnant of the previous operating system (such as a configuration setting) or a hardware problem.

Windows 95 Starts in Safe Mode

If Windows 95 starts in Safe mode, step through the startup process to see if any devices fail to load. To do so, restart your computer, press F8 when you see the "Starting Windows 95" message, and then choose Step-By-Step Confirmation from the Startup menu.

The following table lists several startup options. The options are labeled Boot A, Boot B, Boot C, and Boot D. Try each option and note your results. To use a boot option, press Y or N as outlined in the option in the table below each time you are prompted whether you want to load a particular device. Boot A:

If Windows 95 does not start under these conditions, try the Boot D option. If Windows 95 starts, there is a problem with a driver or terminate-and-stay-resident program (TSR) loading in the Config.sys or Autoexec.bat file, or there is a problem with a Windows 95 protected-mode driver.

Boot B:

If Windows 95 does not start under these conditions, try the Boot C option. If Windows 95 starts, there is a problem with a driver or TSR loading in the Config.sys, or Autoexec.bat file. You can pinpoint the problem by stepping through these files.

There may also be a problem with a TSR loading in the Winstart.bat file if one is present on your computer. Rename the Winstart.bat file and try the Boot B option again. The Winstart.bat file is usually located in the Windows folder, and is used to load TSRs that are required for Windows- based programs, but are not needed in MS-DOS sessions.

For information about how to rename a file, click Start, click Help, click the Index tab, type "renaming" (without quotation marks), and then double-click the "Renaming files" topic.

Boot C:

If Windows 95 does not start under these conditions, try the Boot D option. If Windows 95 starts, there is a problem with a Windows 95 protected-mode driver. For more information about these problems, see the "Troubleshooting Protected-Mode Driver Problems" section of this article.

Boot D:

If Windows 95 does not start under these conditions, try the steps in the "System.ini" section below. If Windows 95 starts, there is a problem with the system registry. For information about restoring the registry, please see the following article in the Microsoft Knowledge Base: System.ini:

To determine whether the System.ini or Win.ini file is causing a problem, try the following steps:

1. Rename the System.ini file in the Windows folder to System.sav.
2. Copy (do not rename) the System.cb file in the Windows folder to System.ini.
3. Add the following line to the [boot] section of the System.ini file and then save the file:

         drivers=mmsystem.dll
   						

4. Rename the Win.ini file in the Windows folder to Win.sav.
5. Restart your computer.

If this works, there is a problem with an entry in the System.ini or Win.ini file. Examine these files more closely to determine the exact cause of the problem.

If Windows 95 does not start when you step through the boot process, start your computer in Safe mode, and then change the video driver to the standard VGA driver.

NOTE: When you copy the System.cb file to System.ini, your mouse may stop working. If this occurs, add the following lines to the appropriate sections of the new System.ini file: For additional information about troubleshooting startup problems using Safe mode, please see the following article in the Microsoft Knowledge Base:

Troubleshooting Protected-Mode Driver Problems

If Windows 95 starts only when you press N at the Load All Windows Drivers? prompt, try the following steps:

1. Start Windows 95 in Safe mode.
2. Use the right mouse button to click My Computer, and then click Properties on the menu that appears.
3. On the Device Manager tab, disable any devices in the following categories:

         Display adapters        Floppy disk controllers
         Hard disk controllers   Keyboard
         Mouse                   Network adapters
         PCMCIA socket           Ports
         SCSI controllers        Sound, video, and game controllers
   						

   To disable a device, follow these steps:
   
   
   1. In Device Manager, double-click the category name, and then double- click the device.
   2. On the General tab, click the Original Configuration (Current) check box to clear it, and then click OK.
   3. Restart your computer.
   NOTE: If Windows 95 does not start, go to the "System.ini" section of this article.
4. Once Windows 95 restarts, enable the devices you disabled in step 3. Enable the devices in the following order:
   
   
   • Com ports
   • Hard disk controllers
   • Floppy disk controllers
   • Other devices
   To enable a device, follow these steps:
   
   
   1. In Device Manager, double-click the category name, and then double- click the device.
   2. On the General tab, click the Original Configuration (Current) check box to select it, and then click OK.
   3. While the properties for each device are open, click the Resources tab and make sure there are no conflicts listed in the Conflicting Devices list.
5. Restart your computer.

Additional Notes

For information about known hardware issues, please see the Hardware.txt file in the Windows folder on your hard disk.

For additional troubleshooting assistance, check the Bootlog.txt file in the root directory on your hard disk. This file lists the loading status of all real-mode and protected-mode drivers. If Windows 95 does not start, the Bootlog.txt file lists the last driver that loaded successfully, and lists a "LoadFail" entry for each driver that failed to load before the problem occurred.