Pre-Windows Startup Troubleshooting


Possibly the most frustrating situation to troubleshoot is when you are unable to successfully start Windows. If something is malfunctioning while Windows XP is up and running, you can use the tools provided by the operating system to try and solve the problem. But, how do you troubleshoot a Windows problem when you can't even get into Windows?

Thankfully, there are also a number of methods and tools available for you to fix a non-starting Windows installation. Some of these options are accessed by using a scaled-down startup version of Windows known as Safe mode . Although, before you try to boot Windows in Safe mode, I do recommend that you try to use the Last Known Good Configuration option discussed later in this section. Before you begin to familiarize yourself with Windows-specific troubleshooting tools and methods, however, you need to be able to recognize and fix errors that can occur before the Windows operating system begins to load.

Common Boot Error Messages and Solutions

The chain of events that takes place when a computer is turned on is known as the boot process . There are a number of steps that take place during the boot process that are entirely independent of the operating system installed on the computer. If an error occurs on a Windows-based PC during any of these steps, the boot process freezes and Windows does not begin to load.

The first step in troubleshooting a nonWindows- related boot error message is to determine which software component is responsible for generating the error message. There are four primary software components that come into play during the boot process:

  • Motherboard ROM BIOS . The Motherboard ROM BIOS is the initial software program that runs upon powering up the computer. It is responsible for testing your system's hardware components, and then initiating the chain of events that leads to the loading of an operating system, such as Windows.

  • Adapter Card ROM BIOS Extensions . Adapter card ROM BIOS extensions are ROM BIOS chips integrated into hardware components such as video cards and SCSI disk controllers. The motherboard ROM BIOS scans for adapter card ROM BIOS extensions, and initializes these devices accordingly .

  • Master Boot Record (MBR ). The Master Boot Record (MBR), as discussed in Chapter 10, "Windows File Systems," is a small program located in the very first physical sector of a hard disk (cylinder 0, head 0, sector 1). The MBR contains the master partition table, which lists all of the partitions on a hard disk. Each partition entry in the master partition table includes information on what type of partition it is (primary or extended), whether the partition is bootable or not, where the partition physically exists on the hard disk, and how many sectors it takes up. In addition to the master partition table, the MBR also contains the instructions used to discover and load the volume boot record from the active (bootable) partition, and a two-byte signature (55AAh) used by the Motherboard ROM BIOS to validate the sector occupied by the MBR.

  • Volume Boot Record . The Volume Boot Record is located in the first sector of the bootable partition on a hard disk. The Volume Boot Record contains information about the volume it resides on, as well as instructions that are used to locate and load the operating system (with Windows XP, the Volume Boot Record is used to find and load the NTLDR file). The Volume Boot Record also contains a two-byte signature (55AAh), similar to the MBR, that is used to validate the sector it occupies.

With this information in mind, here are some common boot error messages and solutions.

Missing Operating System

During the boot process, the Volume Boot Record on the hard disk is tested for a specific two-byte signature (55AAh). If this signature is not found, the error message Missing Operating System is shown, and the boot process freezes.

This error is commonly caused by invalid BIOS settings, usually attributable to a dead or dying CMOS battery. CMOS stands for complimentary metal oxide semiconductor , and refers to a type of RAM chip that is located on the motherboard. The system BIOS reads and writes settings to and from the onboard CMOS chip, which is powered by a small battery so that the settings aren't wiped out when the computer is powered down. One of the settings that the system BIOS reads from the CMOS chip on startup is the hard disk configuration data.

If the CMOS battery is dead or dying, the hard disk settings in the CMOS chip can become corrupted or disappear entirely. Subsequently, when the system BIOS queries the CMOS chip on startup, it receives invalid hard disk settings, which causes the boot process to fail.

Tip

One dead giveaway that you have a failing CMOS battery is if the date and time information in the BIOS setup screen is constantly resetting itself when you power down your computer.


CMOS batteries can usually be replaced . Many computer and electronics stores carry CMOS batteries; you can also check with the manufacturer of your motherboard to see whether they sell them.

No Rom BasicSystem Halted

If the two-byte signature of the Master Boot Record is not 55AAh, the Motherboard BIOS displays an error message. These error messages differ between various BIOS manufacturers. The NO ROM BASIC - SYSTEM HALTED error message is displayed by BIOS ROMs created by American Megatrends, Inc. (AMI).

This error message can be caused by missing boot files, a corrupt boot record, a hard disk failure, or a virus. To repair this issue, boot the system from the Windows XP installation CD, choose to open the Recovery Console, and run the fixmbr command. This will rebuild the Master Boot Record. After completing the operation, eject the Windows XP installation CD and reboot the system.

For more information concerning the Windows XP Recovery Console, see "Recovery Console," p. 556.



If this solution doesn't work, the problem may be attributable to a boot-sector virus. A boot-sector virus copies code onto the partition table of a hard disk. The virus is loaded into memory on startup, which means that in order to attempt to remove it, you need to use a bootable antivirus program disk. If the program successfully locates and removes the virus, you should restore the MBR using the fixmbr command in Recovery Console, and reboot the system.

Boot Error Press F1 to Retry

This error message is generated by the Phoenix Bios when the Master Boot Record is corrupt or missing, or if the system is unable to access the boot drive. This message is the same as the NO ROM BASIC - SYSTEM HALTED message generated by AMI BIOS. See the previous section for details on how to fix this problem.

Invalid Drive Specification

This error is most commonly caused by trying to access a hard disk that hasn't been properly partitioned and formatted yet, or if the master partition table located in the Master Boot Record has been damaged. If you are certain that the hard disk is properly formatted and partitioned, try to restore the MBR using the fixmbr command from the Recovery Console.

Invalid Media Type

This message is generated if the volume boot sector, directory, or file allocation tables are damaged or not yet initialized . One likely cause of this error is if you attempt to access a hard disk that hasn't been formatted yet. Formatting is what creates the Volume Boot Record, file allocation tables, and directories on the hard disk.

If there is data on the disk that you don't want destroyed , you can try to solve this problem by performing a high-level format (also known as an OS format) on the disk. You will then need to unformat the disk using an appropriate utility such as DiskInternals FAT Recovery (which also works on NTFS volumes ) or Norton UnFormat.

Hard Disk Controller Failure

This message indicates that the hard disk controller has failed, or that the controller is unable to communicate with the attached hard disk. Check the drive cables to see if they are properly connected. Also, check if the hard disk is receiving power, and is spinning up when the system is powered on. If these factors are all accounted for, there may be physical damage to the hard disk, the controller, or the data and/or power cables. Try replacing the data cable first, and if that doesn't solve the problem, try replacing the hard disk. If the error still occurs, it's likely that the disk controller on the motherboard is defective.




Upgrading and Repairing Microsoft Windows
Upgrading and Repairing Microsoft Windows (2nd Edition)
ISBN: 0789736950
EAN: 2147483647
Year: 2005
Pages: 128

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