W2000, invalid command.com in DOS box

[Frank Bell]

When I use a DOS program in W2000, and close it, I usually get the message "Invalid COMMAND.COM. Cannot load COMMAND, system halted"

Any ideas as to what causes this, and how to fix it??

Frank Bell

 

[Dan O]

Is a batch file (.bat) used to start the application?

It or the application maybe changing the DOS Path.

Post the batch file and let us know the name of the application.

 

[Rockn]

I think you need the server command to set the DOS version prior to running the app.

 

[JohnWill]

I don't think this error comes from SETVER not being present, it sounds like the application is trying to run a secondary copy of the command processor, or something along those lines. Without knowing more about the application, it's pretty hard to know what is happening.

Does this stop the whole machine, or just kill the DOS app?

 

[Dan O]

John,

That's what I was thinking!

 

[JohnWill]

You're probably right Dan, but without any details, it's hard to know what's going on.

 

[Frank Bell]

Thanks for the thoughts... mostly I'm programming in an old compiler program called Clipper. Using the edit program called "Q" causes the problem, as does linking using the linker program RTLink. Running the compiler (Clipper) doesn't cause a problem, and running the resulting compiled Clipper program usually doesn't cause the problem. I use a batch file to call the compiler and linker, but run Q directly. I tried running Q in the directory it resides in, and the same thing happens... "Cannot load command.com... system halted".

“Q” is q.com, a shareware program I’ve used for 15 years. (Which doesn’t make me a computer expert!)

The batch file is simply:
clipper %1 > ERFIL /B
IF NOT ERRORLEVEL 1 RTLINK FI %1, HELP LIB CLIPPER, NANFOR, CPMI

Thanks for the help!

 

[jdean]

It does sound like something is trying to load a secondary command interpreter. One thing you might try is to make a copy of cmd.exe and call it command.com. cmd.exe is normally lives in your windows\system32 directory; command.com should be placed in the same directory. cmd.exe is not identical to command.com but depending on how it's used, it might work here.

-- Jeff

 

[Frank Bell]

Thanks, Jeff, but both cmd.exe and command.com are already in the system32 folder. So I assume your suggestion wouldn't apply?

 

[JohnWill]

Actually, you might copy COMMAND.COM from WINNT\SYSTEM32 to the directory that you execute "Q" from and see if that makes it happy. I truly believe it's attempting to invoke a secondary command processor, and it's not bright enough to realize that COMMAND.COM isn't in the normal DOS/W9x location. You could also drop COMMAND.COM in the root of C:, where it usually lives in the DOS/W9x world.

I don't think you should be CMD.EXE into the mix, since I'm sure that an old DOS application never heard of that name, so it sure won't find it!

 

[Frank Bell]

Tried that... command.com in the directory I'm running from, and in the root. Same result. But a good idea...

Didn't do this before I upgraded to W2000. Is there a connection?

 

[Rockn]

You might want to install a paralell installation of something like DOS 6 and have dual boot setup.

 

[JohnWill]

Originally posted by Frank Bell:
Didn't do this before I upgraded to W2000. Is there a connection?

There is obviously a connection! W2K/XP is a protected mode O/S, and many older DOS applications that directly access hardware resources fail. Also, applications that took advantage of undocumented or unsupported DOS functions will also frequently fail.

One question, have you tried running the compatibility mode?

HOW TO: Enable Application Compatibility-Mode Technology in Windows 2000 SP2 and SP3

This may do something for the problem, maybe not...

 

[Frank Bell]

In case anyone still looks at this and is interested... I finally solved this (and a few other nagging problems) by doing a clean W2k install. It works fine now.

Thanks for all the help!

 

[Dan O]

It happens to the best of us. I personally use drive imaging to backup and recovery my PCs, such as Ghost or DriveImage. Which allows me to recovey in about 20-30 minutes, not hours or days. A backup should be made right after installing Windows and the core applications. I also do a backup before installing a major new application, but sometimes I forget and if my PC messes up I fall back to my first backup.

Thanks for letting us know you are ok. Happy computing.