16 bit MS-DOS Subsystem: NTVDM CPU illegal operation Solution

I managed to find the solution. I made a full system search on the following files after enabling the "tools -> Folder Option -> Views -> Show hidden Files and Folders" option and remove them.

c:\windows\system32\CMD.COM
c:\windows\system32\NETSTAT.COM
c:\windows\system32\PING.COM
c:\windows\system32\REGEDIT.COM
c:\windows\system32\TASKKILL.COM
c:\windows\system32\TASKLIST.COM
c:\windows\system32\TRACERT.COM

Once those files have been removed, i try to perform those commands listed and all worked!

I got to know that some extensions is executed first when we perform a command, and one way to know is to run "echo %PATHEXT%". The output that was displayed on my laptop are as below (running on Win XP):

>echo %PATHEXT%
>.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH

That might be the reason why I try to perform a "cmd" command in run and was prompted with error, as it triggers the cmd.com program file first before cmd.exe. I wasn't sure why those .com extensions file were there but make sure those files will never exist.