Error Message:



This Stop message indicates that Windows 2000 lost access to the system partition during the startup process. This error always occurs while the system is starting and cannot be debugged because it generally occurs before the operating system has loaded the debugger. During I/O system initialization, the boot device driver might have failed to initialize the boot device (typically a hard disk). File system initialization might have failed because it did not recognize the data on the boot device. Repartitioning the system partition or installing a new SCSI adapter or disk controller might also induce this error.

User Action:

If the error appears while repartitioning the system partition or installing a new SCSI adapter or disk controller on x86 systems, the Boot.ini file must be edited. If the error occurred at the initial setup of the system, the system might have been installed on an unsupported disk or SCSI controller. Some controllers are supported only by drivers that are in the Windows Driver Library (WDL), which requires the user to do a custom installation. If Setup autodetected the controller, you might need to skip detection and use a specific manufacturers disk to load the driver. Also, check the availability of updates for the system BIOS and SCSI controller firmware. Updates of this kind are typically available on the Web site or BBS of the hardware manufacturer. Remove any recently added hardware, especially hard disks or controllers, to see if the error is resolved. If the offending piece of hardware was a hard disk, the disk firmware version might be incompatible with Windows 2000. Contact the manufacturer for updates. If the removal of another piece of hardware resolved the error, IRQ or I/O port conflicts likely exist. Reconfigure the new device according to the manufacturers instructions. Confirm that all hard disks, hard disk controllers, and SCSI adapters are listed on the Microsoft Windows 2000 Hardware Compatibility List (HCL) on If a driver was recently added, restart your computer, and then press F8 at the character-mode menu that displays the operating system choices. At the resulting Windows 2000 Advanced Options menu, choose the Last Known Good Configuration option. This option is most effective when only one driver or service is added at a time. In addition, check your computer for viruses using any up-to-date, commercial virus scanning software that examines the Master Boot Record of the hard disk. This error can also be a result of hard disk corruption. Run Chkdsk /f /r on the system partition. You must restart the system before the disk scan begins. If you cannot start the system due to the error, use the Recovery Console and run Chkdsk /r. Caution: If your system partition is formatted with the FAT file system, the long file names used by Windows 2000 can be damaged if Scandisk or another MS-DOSbased hard disk tool is used to verify the integrity of your hard disk from an MS-DOS prompt. (An MS-DOS prompt is typically derived from an MS-DOS startup disk or from starting MS-DOS on a multiboot system.) Always use the Windows 2000 version of Chkdsk on Windows 2000 disks. If your system has SCSI adapters, contact the adapter manufacturer to obtain updated Windows 2000 drivers. Disable the sync negotiation in the SCSI BIOS, check the cables and the SCSI IDs of each device, and confirm proper termination. For EIDE devices, define the onboard EIDE port as Primary only. Check each EIDE device for the proper master/slave/stand-alone setting. Remove all EIDE devices except for hard disks. Finally, check the System Log in Event Viewer for additional error messages that might help pinpoint the device or driver causing the error. For more troubleshooting information about this Stop message, refer to the Microsoft Knowledge Base at