| Improperly configured hardware can cause your computer to fail to boot at all. This section discusses typical causes and solutions for hardware configuration problems, including problems caused by incorrect drive configurations, damage to disk data structures, boot sector viruses, and SCSI configuration problems. Missing Operating System Error A missing operating system or similar error is generated by the system BIOS's boot loader if it is unable to locate the operating system. Table 20.4 lists typical problems and solutions. Table 20.4. Missing Operating System Error Causes and Solutions | Problem | Notes | Solution | | Incorrect BIOS configuration of the hard disk's geometry (cylinder, head, sectors per track) or LBA mode | If the BIOS values for these settings are altered after the drive is installed, the operating system files can't be located. | See "Auto-detection of the IDE Hard Drive Type" in Chapter 14, "Storage." | | Damage to the drive's master boot record | This section of the drive points to the location of boot files if present. | See "Repairing the Master Boot Record" in Chapter 15. | | No active partition set for the drive | When Fdisk is used to create multiple partitions (primary plus extended), the primary partition must be set as active by the user . | See "Troubleshooting Hard Disks That Can't Boot After Format" in Chapter 15. | SCSI Error Messages If Windows is started from a SCSI hard disk instead of from an IDE hard disk, the configuration of the drive is set by the SCSI host adapter, which must support bootable drives . SCSI error messages can be caused by a variety of problems with how devices (including hard disks and other types of devices) are configured on the SCSI bus. SCSI errors are covered in detail because they differ widely from standard drive configuration errors. caution  | Don't play "mix-and-match" with SCSI host adapters and hard disks. To avoid the potential loss of data, use the same brand (and model if possible) of host adapter if a host adapter must be replaced on a system whose SCSI drive already contains data. |
Table 20.5 lists typical SCSI error messages and their causes. Table 20.5. SCSI Error Messages and Solutions | Problem | Solution | | Device connected but not ready ” No answer was received from a connected SCSI device. | Make sure the device is turned on before the system boots. Set the SCSI host adapter to Send Start Unit Command to the device. Make sure that there are no duplicate SCSI ID numbers . | | Start unit request failed ” Device didn't respond to Start Unit Request command. | Disable Send Start Unit command option for that device. | | Time-out failure during.. . ” A device attached to the SCSI host adapter caused a time-out. | Check termination on the SCSI bus. Both ends of the SCSI daisy-chain of devices must be terminated . Check cables. Loose or damaged cables can cause this problem; retighten cables and restart devices, and then restart the system. Disconnect all SCSI devices and restart the system; if the SCSI card without devices runs okay, one or more of the devices is defective. | | Driver software error messages ” Old DLL or ASPI not loaded. | Download and install new software for the host adapter and ASPI (Adaptec SCSI Programming Interface) or equivalent services for your host adapter. | | Can't access data on a SCSI hard disk after attaching it to a new SCSI host adapter ” Each brand of host adapter uses its own translation schemes to communicate with a drive. | Reattach the drive to the original SCSI host adapter (if possible) and back up data. Attach the drive to the new host adapter and perform a low-level format with the new SCSI host adapter's utility program. This deletes all data on the drive but will allow the drive to communicate with the new host adapter. | | A disk read error occurred after creating a boot partition more than 7.8GB in size . | Enable INT13h extensions in the SCSI BIOS or install a SCSI host adapter that supports INT13 extensions. | |
