Number 265 - June 2005

How I Lost--Then Regained Access To DOS Programs in Windows XP
by Bob Thomson, Tacoma Open Group for Microcomputers
I began using personal computers before MS-DOS became the dominant operating system. But then MS-DOS took over and I switched to that system. Consequently, I still "drop down" into DOS to run several familiar old programs--you know, the ones with .exe and .com extensions. Then along came Windows and, I finally moved to Windows 3.1 and acquired a few programs--among them the software I use to publish this newsletter, PageMaker 4.0. As I have upgraded, I have transferred these early programs and continued to use them in Windows 98 and ME. Everything worked fine, except that some of the new graphic formats were not supported, so to use them in this old version of PageMaker, I had to convert them to basic .BMP files. That was OK because our newsletter is printed in black and white and that format was adequate for the purpose.    When I upgraded to Windows XP I transferred several programs designed to run under the earlier 16-bit version of Windows to the new machine. It took some doing but I eventually had everything running in a manner that I found familiar and satisfactory.    Then, one day, suddenly, I couldn't run any of them.    To an habituated old codger like me that was a nasty shock!    I don't really know what happened. I tried to reestablish an earlier version of the system by running RESTORE to no avail. I was stumped and nobody who I consulted had an answer. One "expert" told me that the latest upgrade of XP (SP2) would not allow old DOS programs to run. I didn't believe him and with good reason as you will see.    Whenever I tried to run a DOS or 16-bit Windows program I would get an error message that said something like:    C:\Windows\System32\Autoexec.nt The system file is not suitable for running MS-DOS and Microsoft Windows applications. Choose 'Close' to terminate the application.    I could use the standard built-in DOS commands like dir but not executable programs. It didn't matter whether it was a simple little EXE or COM program like an alphabetized directory lister or the more elaborate Windows 3.1 version of PageMaker. The same message would come up and the computer operating system would refuse to run the programs.    I have my original Windows XP Pro disk as well as the subsequent SP2 upgrade disk but, of course, I can't reload them because they say that the system is already loaded. I guess I could reformat the hard disk and start over but then I would have to back everything up and start the long process all over. I wanted to avoid having to do that if possible.    After many, many Google searches, downloads and printouts of procedures I finally found what I needed. Even if this isn't exactly what you need, the procedure might help you find a solution to a similar problem. I found my answer in the Microsoft Knowledge Base web site article:    http://support.microsoft.com/default.aspx?scid=kb;en-us;324767    Here I learned how to repair corrupted files using my XP CD- ROM. The site stated: CAUSE    This issue (i.e. The above error message) may occur if one or more of the following files is missing or damaged.     Config.nt     Autoexec.nt     Command.com RESOLUTION    To resolve this issue:    1. Insert the CD into the CD drive or DVD drive.    2. Click Start, and then Run.    3. In the Open box, type cmd, and the click OK,	4. At the command prompt1, type the following commands, (where E: is the CD-ROM drive letter) pressing ENTER after each command:    expand E:\i386\config.nt_ c:\windows\system32\config.nt    expand E:\i386\autoexec.nt_ c:\windows\system32\autoexec.nt    expand E:\i386\command.co_ c:\windows\system32\command.com    Ed note: That is: expand config.nt and autoexec.nt from the CD-ROM i386 directory to the c: drive directory C:\windows\system32. Note that there is a space between nt_ and c:\windows and co_ and c:\windows in the above commands.    5. Start or install the program. If the issue is resolved, do not complete the remaining steps. If the issue is not resolved, go on to the next step....    In my case, the problem appeared to be with the autoexec.nt file so the problem was solved by replacing it and I did not proceed further. If you have this problem and the above steps do not solve your problem go to the above address and read Knowledge Base article 324767 for further steps to take.    I have written this little note for two reasons. Firstly because it solved my immediate problem, and secondly because I learned how to extract files from the Windows XP CD-ROM using the expand command. Of course, you have to know which ones to expand and where to save them but presumably there is a Knowledge Base article that will help in specific situations. Wait a Minute!    Doesn't Windows XP save stuff like this so that repairs can easily done without using the Windows XP CD? Yes it does. During installation these files are expanded into the c:\windows\repair directory. So now, knowing which files you want, from the command C:\> prompt copy the uncorrupted files into the Windows\System32 directory by typing:       copy c:\windows\repair\autoexec.nt c:\windows\system32       copy c:\windows\repair\config.nt c:\windows\system32 or, more simply, since those are the only files in that subdirectory with the .nt extension, using the wild card character *:       copy c:\windows\repair\*.nt c:\windows\system32 again, there is a space between .nt and c:\windows\system32 A Trojan The Cause?    In one source found on the internet says: "The likely cause of this error message is a Trojan virus infection. The Trojan is thought to be: TrojanDownloader.Win32.Dia.a. However, my Norton Antivirus program says my system is clean. Afterwords:    1. I have not found this Trojan, but I have lost access again several times. I have created a batch file to copy lines above by typing the batch filename at the C:\> prompt, whenever I can't load and run my DOS EXE or COM files. In batch files for use in Windows XP it is recommended that the extension CMD rather than BAT be used to avoid problems if accisentally copied to a Win 95/98 system.    2. In the process of researching the solution to my problem I learned that the version of CMD.EXE that comes with Windows XP is NOT the same CMD.EXE that came with earlier versions of Windows. It is a completely different animal written in a different language (UNIX?), using different algorithms but designed to accept and react to commands in a way similar to the earlier version so as to be user friendly.    Perhaps I can expand on this at some later date. Footnote:    1 Command Prompt - For those of you who have never used DOS. The command prompt is C:\>_ where C is the disk drive letter and the blinking underscore character is awaiting entry of a command, such as the expand command lines above.
Number 265 - June 2005