The partition of a disk on which Microsoft Windows NT or Windows 2000 installs core operating system files. These operating system files are stored in the %SystemRoot% and %SystemRoot%\system32 directories on the boot partition.
The choice of boot partition is made during installation of Windows NT and cannot be changed afterward. An important consideration when installing Windows NT is designation of a boot partition that has sufficient free space to contain the operating system files together with all the optional and future components.
The boot partition can be the same as or different from the system partition, which is the partition containing the hardware-specific files for the particular hardware platform Windows NT is installed on (x86 platform or Alpha platform).