User Guide

AntiViral Toolkit Pro
- 63 -
computer hard disk.
BIOS (Basic Input-Output System)
Built-in software included with your computer. It performs functions such as
testing the hardware at start-up, and launching the operating system boot
procedure. It also provides the primary interface to hardware such as the screen,
disks, printers, etc. The BIOS code is stored in ROM.
Boot Sector
The first sector of a logical drive (also the first physical sector on floppies). It
contains the operating system loader code which is executed during boot-up.
DOS (Disk Operating System)
One of many operating systems available for IBM-compatible PCs. It is loaded
from disk and provides a user interface (command prompt) as well as file access
functions for use by applications.
FAT (File Allocation Table)
A data table stored on each logical drive, immediately following the Boot Sector,
which contains information about the location of all the disk clusters in each file.
It also contains data to identify the bad clusters on the logical drive.
MBR (Master Boot Record)
The first physical sector of the hard disk. It usually contains a small loader
routine and the disk partition table. The loader routine analyzes the disk partition
table, selects an active logical drive from it, loads the boot sector of this drive
into memory and then executes it.
TSR
see: Resident
COM File
A simple form of executable file used for small MS-DOS programs which
usually occupy a single segment of RAM.
EXE File
A more complex form of executable file used for both DOS and Windows
programs. There are several different types. Information about the program is
contained within the EXE file header, such as instructions on how to load the file
into memory.