Dealing with Windows Startup Errors






Dealing with Windows Startup Errors

 Time Shaver  Much of the diagnosing and troubleshooting domain of the A+ OS Technologies exam consists of knowing the sequence of events that occurs in the boot sequences of Windows 9x systems, and recognizing error messages and their associated corrective actions. Memorize the boot sequences, and familiarize yourself with the error messages in each environment.

 Instant Answer  If the Windows startup sequence has problems, restart Windows and immediately press and hold down the Ctrl key during the boot process or press F8 after the message Starting Windows 9x appears to display the Startup Menu (from which you can start Windows in Safe mode). Safe mode starts Windows with only the essential device drivers being loaded. If the computer can successfully boot in Safe mode, you know that the problem is in a device or its driver.

Another boot menu option that can help you to isolate a boot problem is Step-by-Step Confirmation. This choice forces the system to boot by displaying system file entries one at a time so that you can include or exclude an entry from the boot process with keyboard entries. Answering No to every option is the same as booting in Safe mode.

 Remember  If Windows won’t boot to Safe mode, the system may have any of the following problems:

  • The CMOS settings are incorrect.

  • A hardware conflict exists, such as advanced BIOS settings, IRQ conflicts, duplicated COM ports, or defective memory modules.

  • The MSDOS.SYS file contains an erroneous setting.

  • The video drivers are not compatible.

You may also want to examine the contents of the BOOTLOG.TXT file, which is located in the root directory. This file contains a log of the results of device driver activation. The last line should list the driver that was attempting to load when the error occurred. If you suspect that the video driver is the problem, set the video drivers to either VGA.DRV or VGA.VXD; you can find both on the Windows CD-ROM.

Friendly Windows 9x error messages

Because DOS and Windows 3.x used up all the really good error messages, Windows 9x systems have had to resort to messages that actually make sense on occasion. Some of the very best error messages (or lack thereof) that Windows 9x has to offer are as follows:

  • (No error message): The startup stops at a point after the POST but before Windows starts, but no error message is displayed. Run FDISK from a command-line prompt with the /MBR option to rebuild the MBR (master boot record). You may want to scan the disk with an antivirus program first, because the problem may be a boot virus or some equally scary problem with the MBR.

  • General Protection Fault in USER.EXE: The User core component has run out of file space. Add the line FILES=100 to the CONFIG.SYS file to fix this problem.

  • 0E or 0D exception: 0E errors refer to bad memory, and 0D errors are video problems. These errors are usually displayed on the “blue screen of death.” Restart the system to clear the error. If the problem persists, check the CMOS for exceptions and verify the device drivers that are in use. To avoid the problem, try switching to standard VGA video mode.

  • Out of Memory: This error is caused by memory leaks — programs that end without releasing their memory allocations. Reboot the system and reduce the activity on the system.

Booting Windows

Typically, when you start up your Windows 9x PC, the operating system runs through its normal startup procedure, which ends by displaying the desktop on the screen and showing all the applications that are included in the startup procedure running in the system tray. However, for the A+ OS Technologies exam, you should know how to access the Startup menu and start Windows 9x and Windows 2000 from it. You should know what each selection on the Startup menu does.

Changing your boots

To access the Windows Startup menu, you can either

  • Press and hold down Ctrl while the PC is booting

  • Press the F8 key right after you hear a beep, after the Starting Windows message displays, or when the Windows splash screen appears

 Remember  The Windows 9x Startup menu includes the following entries:

  • Normal: This selection is just what it sounds like: the normal Windows boot. Choosing this option (by entering 1) continues the standard boot process.

  • Logged (BOOTLOG.TXT): This selection completes a normal startup, but all startup actions are recorded in the BOOTLOG.TXT file in the root directory or on the startup disk.

  • Safe mode: This selection completes the startup but bypasses the system files and loads only the essential system device drivers. You can go straight into Safe mode during the startup by pressing F5 right after the Windows splash screen appears (in Windows 98, Me, 2000, and XP) or by entering WIN /D:M at a command-line prompt.

  • Safe mode with network support: This selection starts Windows in Safe mode but also loads the drivers that allow access to a network.

  • Step-by-step confirmation: This selection allows you to confirm each of the actions that are contained in the system files one at a time. For each action, you are required to respond with a Y or an N to start the action or not to start it, respectively.

  • Command prompt only: This selection starts up the operating system and loads the normal system files and the Registry but displays only a command-line prompt in place of the Windows desktop.

  • Safe mode command prompt only: This selection starts Windows in Safe mode but displays only the command-line prompt.

 Remember  The function-key options that can be used to select the Windows startup options are controlled by the BootKeys variable in the MSDOS.SYS file. If the BootKeys variable is set to 1 (the default), the function keys are available for use during startup. Setting this variable to 0 or setting the BootDelay variable to 0, which removes the delay that allows you to press a function key, removes the ability to use function keys to change the startup process.

When Windows won’t boot

If Windows does not start normally, you should try to start it in Safe mode, which bypasses the real-mode drivers and configuration and loads a minimal protected-mode configuration that disables the Windows drivers and provides only a VGA display.

However, if Windows will not start in Safe mode, one of the following conditions is likely the cause:

  • The PC is infected with a virus. Install and run an antivirus program on the PC.

  • The CMOS settings are wrong. If you can access the BIOS setup program and the configuration data, check them for accuracy. Hopefully, you have a paper backup of what the CMOS settings should be. If not, you may need to contact the manufacturer to get the CMOS settings.

  • A system resource or hardware conflict exists. Check for IRQ conflicts, duplicated COM ports, PCI BIOS settings, and possible defective RAM.

  • MSDOS.SYS has an incorrect setting. Verify that no incomplete or invalid settings exist in this file.

  • A DriveSpace drive cannot mount a compressed volume file (CVF). Follow the procedures in the Windows Help files for CVF files and for troubleshooting DriveSpace.

  • A Registry error exists. Boot to the Command prompt only startup option and run SCANREG from the command-line prompt. See the preceding section for information on Windows startup options.

When all else fails, reinstall Windows into a new folder to determine if the problem is something that was left over from the previous operating system or Windows version.

 Instant Answer  If Windows boots to Safe mode, you should step through the startup process using the Selective Startup option of MSCONFIG (executed from the Start menu’s Run box) to try several different startup options.

Using Device Manager to isolate startup problems

 Remember  If a PC boots to Safe mode but the problem remains unsolved after scanning the Registry and startup process, the problem may be hardware related. Follow these steps to use Device Manager to help isolate the problem:

  1. Open Device Manager from the Control Panel’s System icon or by right-clicking the My Computer icon and choosing Properties.

  2. On the Device Manager tab, disable all the devices that are listed under the following device trees by right-clicking each device, choosing Properties, and checking the Disable in This Hardware Profile box, as shown in Figure:

    • Display adapters

    • Floppy disk controllers

    • Hard drive controllers

    • Keyboard

    • Mouse

    • Network adapters (if present)

    • Ports

    • PCMCIA socket (if present)

    • SCSI controllers (if present)

    • Sound, video, and game controllers

      Click To expand
      Figure: The Disable in This Hardware Profile check box is used to disable a device in Device Manager to isolate hardware problems on a Windows system

  3. If the PC starts without the problem, begin enabling the devices in the following order until the problem repeats:

    • COM ports

    • Hard drive controllers

    • Floppy disk controllers

    • Other devices

  4. Restart the PC after enabling each device. Also, check the Resources tab for each device to see whether any problems are shown in the Conflicting Device List.

Using Automatic Skip Driver

The Automatic Skip Driver (ASD) agent attempts to enable any disabled device that may be causing the startup problem and reports the problem. The ASD tool is located on the Accessories menu. To access the tool, choose Start ® Programs ® Accessories ® System Tools ® System Information ® Tools ® Automatic Skip Driver Agent.



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