DIT314 ~ Client Operating System & Administration CHAPTER 4 CONFIGURING HARDWARE DEVICES AND STARTUP PROCESS Prepared By : Suraya Alias

4.5THE STARTUP PROCESS Startup Phases (sequences) Power-on self test (POST) phase Initial startup phase Boot loader phase Detect and configure hardware phase Kernel loading phase Logon phase This sequences applies only to the system that was shut down ad restarted normally, not applicable for hibernation and standby mode

4.5THE STARTUP PROCESS For Win XP to start, the systems and boot partitions must contain below files FilenameDescription NtldrThe operating system loader Boot.iniContains the OS choices that display on startup menu Bootsect.dosHidden system file loads by Ntldr, used for multiple-boot systems Ntdetects.comFile that passes info about the hardware configuration to Ntldr Ntbootdd.sysThe device driver used to access devices attached to a SCSI or ATA h/disk whose adapter is not using BIOS Ntoskrnl.exeThe kernel of Win XP operating system Hal.dllHardware Abstraction layer (extract h/w details from OS and provide interface to devices) System registry fileContains the data used to create registry key HKEY_LOCAL_MACHINE\SYSTEM. Device driversDriver files for h/w devices, such as keyboard, mouse and videos

4.5THE STARTUP PROCESS Preboot sequences 1. Computer runs POST routines to determine the amount of physical memory, whether the hardware component are presents. Check plug and play compatible BIOS and hardware configuration 2. The comp BIOS locates the boot device, loads and runs the Master Boot Record (MBR) 3. The MBR scans the partition table to locate the active partition, loads the boot sector on the active partition in memory the executes it 4. The computer loads and initializes the NTLDR file

4.5THE STARTUP PROCESS Problem that can occur during Preboot sequences 1. Improper hardware configuration or malfunctioning hardware Usually message hard drive cannot be located 2. Corrupt MBR If MBR becomes corrupted (virus), can be repaired back using Recovery console or using Anti virus s/w 3. Floppy or USB inserted Message non system disk or disk error, or No OS is found, maybe USB is inserted during startup

4.5THE STARTUP PROCESS Boot sequences After NTLDR has been loaded into memory, the boot sequence gathers information about the hardware and drivers in the preparation for Win XP load phases. The boot sequences uses these files; NTLDR, BOOT.INI, BOOTSECT.DOS (optional), NTDETECT.COM & NTOSKRNL.EXE The 4 phases of boot sequences 1. Initial boot loader phase 2. Operating System Selection 3. Hardware Detection 4. Configuration Selection

4.5THE STARTUP PROCESS BOOT.INI file Boot.ini is saved in active partition when we install Win XP. NTLDR uses information in boot.ini to display the boot loader screen, from which you select the OS to start. Boot.ini includes two section [boot loader] and [operating system] which contains information that NTLDR uses to create the Boot Loader Operating System Selection menu Example [boot loader] timeout=30 default=multi(0)disk(0)rdisk(0)partition(2)\WINDOWS [operating systems] multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Microsoft Windows XP Professional" /fastdetect multi(0)disk(0)rdisk(0)partition(2)\WINNT="Windows 2000 Professional" /fastdetect

4.5THE STARTUP PROCESS Troubleshooting the Boot Sequence (Problem) 1. Missing or corrupt boot files If the NTLDR, BOOT.INI, NTDETECT.COM & NTOSKRNL.EXE files become corrupt or missing, the error message indicating the situation and windows startup fails 2. Improperly configured BOOT.INI If manually edited, or change the configuration. If BOOT.ini corrupt, use the Recover console 3. Improperly configured hardware NTDETECT.COM cab fail during its detection of hardware if the h/w is wrongly configured, bad driver or malfunctions Use step by step of removal, uninstalling the devices and adding it one by one at a time

4.6EDITING THE REGISTRY Win XP stores hardware and software settings in a hierarchical database called the Registry (replaces the.ini,.sys and.com configuration in previous windows) Registry controls the Win XP OS by providing information in starting applications, load components and devices also network protocols Registry Hierarchical database that contains data includes; The hardware installed in computer (cpu, bus type..) Installed device drivers Installed applications Installed network protocols Network adapter card settings

4.6EDITING THE REGISTRY Components that access and store data in registry 1. Windows XP Pro kernel 2. Device drivers 3. User profiles 4. Setup programs 5. Hardware Profiles 6. NTDETECT.COM