FOR NOW BELIEVE ME, LATER WHEN YOU BECOME A "GEEK" YOU CAN ARGUE WITH MY REPLACEMENT ABOUT THE ACCURACY OF WHAT I WRITE. Otherwise, You can argue with my replacement now, if you can find IT.

For now, lets assume we are discussing an AT compatible PC, with a hard drive (C:) and MS-DOS as the operating system. Thanks, Jim Shuler

Lets look at the boot process, and hopefully, it will help you understand the importance of the operating system.

The following might be a "step-by-step description of the DOS "BOOT" process:

1. Power is turned on (You flip the power switch to the "ON" position).

2. The power supply is activated, and electricity flows through the computer's circuitry.

3. The power flow follows the "bus" to the CPU, and clears the internal memory registers, resets the program counter to the "address" of the ROM chip that contains the Basic Input/Output System (BIOS). The BIOS chip can usually be located near the CPU. It will often be labeled "Vendor-Name BIOS" and is approximately a 1 inch square, flat chip with many small etched circuits going from the mother board into it.

4. The CPU starts the BIOS from its chip; and BIOS starts the "power-on self-tests" (POST).

5. The CPU then checks to the system "BUS" to ensure that a the bus and devices can be touched. It also tests "memory", the video adapter, and the keyboard.

6. If the above checks out ok, it then ckecks the results of each of the POSTs against the 'setup' in the 'CMOS' chip. If they match, it continues to boot, otherwise you get the dreaded message

   "...press (F2) for setup, (F1) to continue."

7. If the CMOS and BIOS POST matched, you will have the operating system loaded from the boot device (probably the C: drive, but could be the A: drive, or other primary drive on your hard disk.). CMOS (the setup) tells the CPU which drive to use for booting.

8. The "boot record" is on the boot device (floppy or hard drive). It is located on the disk's first sector. The "boot record" contains the instructions to load the "hidden" files "IO.SYS" and "MSDOS.SYS" (if DOS) into RAM.

   NOTE: IF you had Windows 95, or Windows NT, or someother operating system the step above would load that operating system. Sorry, computers get a little complex based on the operating system they use. Each operating system does things differently - but the same - huh??

9. Now, the commands in your "config.sys" file are executed. If you know what the "config.sys" file is.

10. Next, the "command.com" file is loaded into memory along with the BIOS which then becomes part of the permanent operating system in memory. THEN, the "internal commands" are loaded into the high end of conventional memory.

11. Next, "command.com" will execute the "autoexec.bat" file, if it exists.

12. Your computer should now be booted and ready for use. It may show the "C:\>" prompt or something else.

FOR NOW, PLEASE HAVE A LITTLE FAITH: You will learn what each of the things mentioned above are, and what they do. HANG IN THERE FOR A LITTLE WHILE!