Copyright Goodheart-Willcox Co., Inc. 68 Computer Service and Repair upgraded to a new operating system that uses UEFI fi rmware and supports the GUID partition table, the UEFI technology will use CSM to support a BIOS MBR partition. Th is way, backward compatibility is maintained. Windows operating systems began support for EFI and UEFI with the release of Windows Vista. Windows operating sys- tems must be 64-bit versions to use UEFI. Windows 8 was designed with a secure boot sequence to prevent malware and unauthorized changes to the operating system. By default, Windows 8 installs the boot sequence for the use of UEFI fi rmware. Windows 8 does have the ability to run on computers designed with BIOS, but some of the security features will not be installed because BIOS cannot implement these features. UEFI fi rmware protects the computer before the start of the Windows 8 operating system. Th e UEFI system al- lows the antimalware program to begin before the operating system starts. Th e early start of antimalware software helps to prevent attacks on the computer before the operating system is loaded. Also, Windows 8 only allows the installation of Microsoft preapproved software applications. Th e purpose of this is to prevent malware ap- plications from altering or damaging the system confi guration. Th ere will be much more about UEFI protection later in Chapters 15 and 16. Windows Boot Sequences Starting with Windows Vista, Microsoft made several changes to the boot sequence. For example, Windows Vista and later operating systems will boot from either the BIOS or UEFI. In Windows 10, after the POST completes, the fi rmware boot loader boots the UEFI instead of using the BIOS, which shortens boot times and supports more options than BIOS such as loading OEM UEFI applications. Th e next phase for Windows 7, Windows 8, and Windows 10 is the Windows Boot Manager phase. In this phase, the Windows Boot Manager (bootmgr) reads a registry-type fi le called the Boot Confi guration Data (BCD) fi le. Th is fi le stores boot confi guration information, such as the names of the operating systems to list in a boot menu, the amount of time the boot menu should be displayed while waiting for user input, and the default operating system to load if no user input is entered. Th e Windows Boot Manager (bootmgr) replaces bootcfg.exe used by older Windows NT-based operating systems. Th e Windows Boot Manager will not display a selection of operating systems if there is only one operating system on the comput- er. If there are two or more operating systems, the Windows Boot Manager appears for approximately 30 seconds to allow the user to select which operating system to boot. If no selection is made, the default operating system is started. When the Windows Boot Manager phase completes, the Windows Boot Loader (winload.exe) phase begins. First, the kernel (ntoskrnl.exe) is loaded into mem- ory but not executed. Th e hal.dll fi le and registry data are also loaded into memory. Th e Windows Boot Loader phase ends by executing the kernel. Th e kernel-loading phase begins. In this phase, the kernel starts the Session Manager (smss.exe), which creates the system environment. Up until now, the operating system has been in a text-based mode however, with smss.exe loaded, the operating system switches to graphics mode by loading the GUI. It is at this point that the familiar progress bar appears at the bottom of the screen. Th e kernel interacts with hal.dll and the registry information in memory to load hardware drivers and other fi les necessary to complete the boot operation. Th e last phase in the boot sequence is the logon phase, which is initiated by the loading of the Logon Manager (winlogon.exe). After a successful user logon, the desktop appears, and the user can start using the various software applications. TECH TIP Because the term BIOS is so ingrained in computer techni- cian jargon, it will still be used for many years to represent the correct term fi rmware and UEFI. Although not techni- cally correct, this is the way technical language commonly evolves. You will often encoun- ter terms that are not always correct when reading resource materials and talking to other technicians. A+ NOTE When answering questions related to the Windows 7, Windows 8, and Windows 10 boot sequence, remember these operating systems use the Windows Boot Loader fi le, winload.exe, not the legacy ntldr.