Boot loaders load kernel images into memory and hand control of the CPU over to the newly loaded kernel. To make your new kernel work, you must tell the boot loader about the kernel.
If you have never worked with a boot loader before, you need to know how a PC boots from the hard disk. On a normal Microsoft-based system, the boot process works like this:
After performing the power-on self test (POST), the BIOS loads sector 1 of the hard disk into memory and runs whatever landed in that memory. On most Windows-based systems, this sector is called the Master Boot Record (MBR).
The MBR extracts the partition table from the disk and identifies the "active" partition.
The MBR loads and runs yet another boot sector ...