China DOS Union

After deleting cmd.exe or setting permissions, it was found that command.exe became "invalid" and there was no response when typing commands. This is the case for XP, 2K, and 2K3 systems~! Could it be that command depends on cmd?

Hearing you say that, it seems so. I haven't tried it

It can be understood that Cmd.exe provides a most basic environment.

Shouldn't be like this.
The command is just an entry to a sub-environment of ntvdm.
There's no necessary connection with cmd.
If ntvdm.exe is gone, the command will prompt that command is not found.

Originally posted by qzwqzw at 2009-4-10 03:51:
It shouldn't be like this
command is just an entry point of a sub-environment of ntvdm
There is no necessary connection with cmd
If ntvdm.exe is gone
command will prompt that command is not found

Really is like this! If you don't believe it, you can check it on your own computer!

That's right. The DOS emulators and OS/2 emulators in the NT environment both need the cmd.exe command-line interpreter.

Well, some strange places were found

Originally, I only tested that being able to open command.com was considered to work normally

It was found that many commands did not execute and output

Currently, the acceptable and executable commands tested are:

Drive letter jump c: d: e: and so on
Path jump cd
Prompt display and modification prompt
(And using prompt $t can get the system time)
Environment exit exit
Environment variable operation set

Through the tracking of procmon, it can be confirmed that ntvdm.exe does call cmd.exe to implement some command-line functions, including dir, cls, etc., and it is called using a very traditional interface. C:\WINDOWS\system32\cmd.exe /c DIR. But there are no such calls for commands like cd, prompt, etc.

Learning