In the Windows 2000 or in later versions of Windows which hibernation is supported, the Windows boot loader starts the search for operating systems by searching for "hiberfil.sys". NTLDR looks into the root folder of the default volume specified in boot.ini. Windows Boot Manager looks up the location of hiberfil.sys in BCD. If this file is found and an active memory set is found in it, the boot loader loads the contents of the file (which is a compressed version of a physical memory dump of the machine) into memory and restores the computer to the state that it was prior to hibernation.