I have to say, this was an idea I had thought about years ago. If you want to be free of viruses and trojan horses and other malicious software while surfing the internet, the BEST way to go about it is to boot your operating system from a non-writable CD-ROM disk. The US Department of Defense so believes in this technique that they have created their own version of Linux specifically for this purpose!
(click here for the original article that inspired this post)

So technically, how does this work? Well, when you start your computer, the usual steps involved include your computer starting your operating system (like some variant of Microsoft Windows) from your hard disk. Once that is started, you are free to go about your computing business. But malicious software that makes its way onto your computer wants to be run every time you turn on your computer. So how does it do this? It modifies the startup files to your operating system on your hard disk so that every time you turn on your computer, the malicious software becomes active each time.

Well, the folks from the Department of Defense are suggestion that instead of booting your computer from a hard drive, you insert something called a “live CD”, which is an operating system (perhaps like windows) that starts up from a CD ROM disk (or DVD), rather than the hard drive. The key here is that the disk used to start the operating system is NOT WRITABLE. Since CD ROM and DVD-ROM discs cannot be written to after they have been created (assuming here that you have correctly created the CD-ROM disc, closed the writing session, etc.). It then becomes much more difficult for the malicious software to get “entrenched” onto your computer such that it will activate each time you start your machine.

Of course, in the world of technology there are few (if any) “absolutes”, but this method *IS* a powerful one to prevent having one’s computer from being infected by malicious software.

I don’t know if there are any “live CDs” of Windows operating systems. I don’t know because I personally don’t use Windows in that manner. However, there are many Linux “live CDs” out there in the world. Linux is a different operating system from Windows, but for simple surfing the internet and similar tasks, it is fairly easy to get running (indeed, in most cases you just insert the live CD and power up the machine).

Anyway, I just thought I would comment on this story as I felt it was worth understanding how and why booting from a CD or DVD was a good idea under the right circumstances.