I often have to boot under DOS in order to perform some maintenance things - re-format or re-partition hard disk, do virus diagnostics or recover files.
I love using fdisk, or McAfee viruscan in command line mode. I love typing "fdisk". For that, MS-DOS command line is nice.
Booting from a flashdisk is faster than floppies, and a flashdisk a lots more space than a floppy.
So, now, how to boot from a flashdisk without complicating or dangerous things ?
Here is the way I do it. Of course, I found the trick from several places on the Internet, but nobody gave the step-by-step I needed, that's why I wrote my own one, here it is.
My own USB flashdisk is a Cosk*in 2gb, from http://www.cosk-in.com
First of all, let's see if your PC is able to boot from a flashdisk.
Let's first power off your PC (correctly shutting down Linux or Crosoft Windows)
1. Testing the hardware.
Insert your USB flashdisk in a USB port, and power on your PC. Then, go to the BIOS SETUP menu (usually it's F2).
Then look at the "BOOT" section. Depending on your BIOS version, have a look at the first boot device, it can be seen as a removable device or a hard disk. Of course, before changing anything here, you must carefully write down the initial settings in order to be able to come back in case of trouble.
If the BIOS sees your flashdisk as a removable device, choose it as first boot device.
If your flashdisk is seen as a disk, you have to put this disk as first disk.
Save your settings and exit.
2) Making the flashdisk bootable.
Now, go to a very old computer running windows 98. I know, sometimes it's rather hard to find one. Personnally, I used a vmware virtual machine on my brand new PC.
When you are on your Windows 98 or Windows Millenium system, download the drivers for your USB flashdisk. This will probably need a reboot.
As soon as your flashdisk drivers are installed, you will be able to see your flashdisk files using Microsoft Windows Explorer. Remember the name of the concerned disk. Let's let's suppose that your USB disk drive name is "U:"
Then, open a command prompt windows (for instance click Run --> Execute --> command)
At the DOS command prompt, type :
CODE
SYS U:
This "sys u:" command transfers on your USB flashdisk the system files needed for booting your flashdisk, exactly like it would do it on any standard disk. One of this files you probably already know, it's the well-known "command.com" file.
The other files are IO.SYS and MSDOS.SYS
That's all. You made your flashdisk bootable. And you already know it's harmless, because you simply added some files to your flashdisk. If you want to go back, simply remove these files.
Now the most interesting thing :
3) Boot from the flashdisk.
Everything is setup. While your system is powered down, insert your USB flashdisk in any free port, and power on your pc.
After a couple of seconds you will see the popular C> prompt. You may type VER in order to verify the version.
That's all you can do at that point. But if you inserted some more files (like format.com or fdisk.com) you have a working ms-dos system.
Further you may add mouse.com, or probably and autoexec.bat or and/or a config.sys file.
4) Discussion.
I love this method because it's simple and harmless. You do almost nothing special on your flashdisk, you just add a couple of files.
I used some other more sophisticated tools from the internet, they started by a flashdisk reformat (and I lost all my favourite files) and then they did not work.
That's why I love this way using an old win95 system and just type "sys U:"
( no one prefer to sell this type of handset)
