By Val Bakh 1. Vista 1.1. Boot architecture
All Windows versions that are designed for business, starting with Windows NT include built-in support to multiboot configurations. Multiple instances of Windows can be installed on the same computer. When the computer starts, you can choose which instance to boot from. The multi-boot architecture in legacy Windows versions is based on a Boot.ini text file. You can edit the Boot.ini text file using a text editor such as Notepad to control the boot menu.
Windows Vista and subsequent Windows versions use a different boot architecture. Instead of using Boot.ini Windows Vista stores information about available operating systems and corresponding hard drive partitions in a binary structure called the Boot Configuration Data store (BCD). It is easiest to set up a computer to multiboot between multiple versions of Windows. This is done by installing all previous versions first, and then installing the newer versions, such Windows Vista. Windows Vista detects older versions of Windows and creates a special entry in its boot menu. If you choose an Earlier Version of Windows in the boot menu, control is transferred to legacy startup code. This displays a secondary boot menu based on entries in a Boot.ini.
The default operating system is the Windows Vista instance that was installed last. To manage the BCD store fully, you can use the Bcdedit command line tool. You can also use the Bcdedit command-line tool to modify the default entry in your primary boot menu. To do this, simply open System in Control Panel on any Windows Vista installation. Click Advanced system settings, then click Settings in Startup and Recovery. Select the appropriate item from Default operating system drop down list box.
Let’s say your computer is running Windows XP and Windows Vista. It is set up for dual boot. What if you have to reinstall Windows XP because of some reason? You will then be unable to boot to Windows Vista because Windows XP will modify the boot code. You can reinstall Windows Vista by following the instructions in Windows XP. You might be able to use Bcdedit for Windows Vista installation recovery. You don’t need to reinstall Windows Vista. There is an easier way. The second question is not answered. You cannot use Bcdedit for dual-boot restoration.
Why not? Bcdedit is able to fully manage BCD. It can either create a new BCD shop from scratch or rebuild an existing BCD shop. Your BCD store is in good condition and has not been damaged. Only the boot code was changed when you reinstall Windows XP. Bootsect is a command-line tool that can restore dual-boot capability. It is found in the boot directory and is included on any Windows Vista installation DVD. You will need to boot to Windows XP and insert a Windows Vista installation dvd. Next, run the following command at the command prompt: E.bootboosect /nt60 sys. E is the letter that corresponds to the DVD drive. This command will change the boot code of the system volume to Windows Vista.
The Windows XP installation only changed the boot code, but left the original BCD file intact. There is no need to take any further action to restore dual-boot capability.
1.2. 1.2.
Let’s say you need Windows Vista installed on a new computer. How do you start the computer? The obvious answer is to boot the computer from a standard Windows Vista DVD. What if you need Windows Vista to be installed on multiple computers? You could use a network boot disk with earlier versions of Windows. However, you can’t create one for Windows Vista. The answer is no. It is not true.