Copyright Goodheart-Willcox Co., Inc. 69 Chapter 2 Operating Systems Certain fi les are automatically loaded into RAM after a successful user logon. Th ese fi les are generally referred to as startup programs. Th ey will start quickly after they are selected from the Start menu or from a shortcut icon because they are already loaded into RAM. If a program is not a startup program, it will need to be loaded to RAM before it starts, thus causing a short delay in program response when selected. Th e following details Windows 7, Windows 8, and Windows 10 boot sequence: For Windows 7 and 8 1. BIOS performs the POST. 2. BIOS fi nds the boot location via the MBR and loads it into memory. 3. BIOS locates and loads the Windows Boot Manager (bootmgr). For Windows 10 1. Firmware performs the POST. 2. Firmware boot loaders bootstrap the UEFI environment (think mini-OS). 3. Run any SoC vendor, Microsoft, or OEMs UEFI level applications. 4. UEFI fi nds the boot location via the GUID partition table (GPT). 5. UEFI launches the Windows Boot Manager (bootmgr). Common steps Windows 7, 8, and 10 A. Windows Boot Manager reads the BCD fi le and displays the boot menu. B. Windows Boot Manager starts the Windows Boot Loader (winload.exe) when Windows 7, Windows 8, or Windows 10 is selected or if started automatically. C. Th e Windows Boot Manager loads ntoskrnl.exe and hal.dll into memory and scans the registry for device drivers to load. It then passes control to the kernel. D. Th e kernel loads the device drivers and hal.dll and initializes the computer settings using the values stored in the system registry. E. Th e kernel starts the Session Manager (smss.exe), which creates the system environment. F. Th e operating system switches to graphics mode and the winlogon.exe fi le is loaded, thus starting the Logon Manager (winlogon.exe). G. Th e Logon Manager allows the user to begin the logon process. Dual-Boot and Multiple-Boot Systems When two operating systems are installed on a single computer, it is referred to as a dual-boot system. For example, Windows 8 and Windows 10 can both be installed on the same computer, resulting in a dual-boot confi guration. Th e Windows Boot Manager or a third-party boot loader such as GRUB allows the user to select which operating system to start. If no selection is made, the Windows 10 operating system will start by default. You could also confi gure a multiple-boot system, which contains more than two operating systems. For example, you could have Windows 7, Windows 8, and Windows 10 installed on the same computer. You could also add a non-Microsoft operating system, such as Linux. A multiple-boot system is often referred to as a multiboot. Virtual Machine When a computer is confi gured as a dual-boot or multiple-boot system, you can only run one operating system at a time. However, a virtual machine can be created using TECH TIP You can create a dual-boot system with Windows 10 by making a spare partition on your system drive and loading it with any legacy versions of Windows, such as Windows XP, Windows Vista, Windows 7, or Windows 8. 1002: 1.3 1001: 3.8