DOS Can Help Kill Stubborn Virus/Rogue File

Recently, I received a call from an old friend and former workmate with a tech support question related to virus removal. He was very concerned that Norton's virus detection software found a back door virus in the Microsoft Windows, but was unable to access the file to access or quarantine it.

That's a common problem with Windows if the infected file is actually in use by the operating system. It's a lot like a puppy trying to catch its own tail and ends up going in circles. The easiest way to solve that problem is to restart your computer in the "safe" mode or restart and continue to strike the "F8" key as the computer restarts.

Eventually, you will see a screen asking you how you want to proceed by going into the safe mode, the normal mode or several flavors of pseudo DOS. Select "Safe" and your computer will go into Windows but not load any startup programs, file or drivers.

Usually, it's very easy to run your virus program again and it should detect the offending file again and either remove or quarantine it.

But, sometimes Windows can be quirky (grin). The virus detection program may fine the bad file, but for some unfathomable Windows reason, not delete it.

That's the time when a little old-fashioned knowledge of DOS will come in handy. I daresay that a good percentage of today's computer users have no idea what DOS - short for disk operating system - is or does.

Before Windows and the Graphic User Interface, REAL computer users only had DOS-based programs to get their work done. It was kind of like owning a car with an engine you could tear down and work on and then put back together yourself.

Early version of Windows made it east to get to DOS, but today, you must go to "start" and then "run" to reach what's called a "command line" of what passes for DOS in today's Windows world.

There will be a box into which you need to type "cmd" - that stands for "command" and you want to play around in DOS.

You will be greeted with s cryptic screen and a line of text probably like this: "c:\Documents and Settings\" and maybe your name. You are actually in the directory for your documents and settings, and need to go somewhere else.

Let's say that Norton's says the offending file is located in the "C:\frank\john.exe" . Of course, that's not a real file for most folks, but you get the idea.

From the command line type (all without quote makes) "cd \" . This will take you to the "top" of your file structure; the command "cd" literally means "change directory."

Next type the path to the bad file's directory by typing (in this case) "cd c:\frank" and hit enter. Your black screen should now read "c:\frank".

Make sure the file is there by typing "dir john*" This literally means show me a directory of files that have "john" as part of the file name. That will find "john.exe" if it is in that directory.

If you see a file that says "john.exe" congratulations! You have found the lair of the offending file. Next, just type "del john.exe" and hit enter. That tells the computer to delete the file from the hard drive.

Yes, it seems like a lot of work, but the best way to remove the virus file if you can't get to it in Windows.