Windows 7 and Windows Vista utilize four boot files, and you will need an understanding of all four of them for the A+ Certification exams. The four boot files for Windows 7 and Vista are:
bootmgr: Operating system loader code; similar to ntldr in previous versions of Windows
Boot Configuration Database (BCD): Builds the operating system selection menu; similar to boot.ini in Windows XP, but data resides in the BCD store. You can edit the boot configuration data with the bcdedit utility.
winload.exe: Loads the Vista operating system if selected from the operating system selection menu provided by BCD
winresume.exe: Resumes the Vista operating system if the system is started from a hibernate state
