What is the partition?
The partition sector is the first sector on a hard disk. It contains information about the disk such as the number of sectors in each partition, where the DOS partition starts, plus a small program. The partition sector is also called the “Master Boot Record” (MBR). When a PC starts up it reads the partition sector and executes the code it finds there. Viruses that use the partition sector modify this code. Since the partition sector is not part of the normal data storage part of a disk, utilities such as DEBUG will not allow access to it. [Unless one assembles into memory] Floppy disks do not have a partition sector. FDISK /MBR will change the code in a hard disk partition sector.