Abstract: An apparatus and method of replacing the Master Boot Record with an installation code which retains compatibility with any disk partitioning or formatting utility that uses the system's BIOS to access the disk is disclosed. The Master Boot Record which is generally located on cylinder 0, head 0, sector 1 on a disk drive is replaced with a new BIOS loader and BIOS extension code. The BIOS loader determines the location in memory to load the new BIOS and updates the interrupt table. Upon completion of initialization, the new BIOS returns control to the BIOS Boot loader which requests the BIOS to load sector 1, head 0, track 0 to memory and then transfers control to it. The newly loaded BIOS extension redirects the request for this particular sector from 0/0/1 to the highest commonly available sector for cylinder 0 and track 0. Thereafter, all utilities which require access to the Master Boot Record will be transparently re-directed.