what is the name of the program that reads the settings in the boot configuration data (bcd) file and manages the initial startup of the os
For traditional BIOS boot, the file is at \boot\BCD on the active partition. Boot Configuration Data may be altered using a command-line tool (bcdedit.exe), using Registry Editor (regedit.exe), using Windows Management Instrumentation, or with third-party tools such as EasyBCD, BOOTICE, or Visual BCD Editor.