Problem

When you start your Windows Operating System, a popup appears related to updatemgr.exe stating that “The NTDVM CPU has encountered an illegal instruction”. This should be closed or ignored. I mean to say that there are two options with this error at a glance. Either you can close it or you can ignore it.

After you close it or ignore it, nothing happens. It’s all fine with your computer and your system. But the main problem is that it appears all the time when you start your computer. And nobody wants a kind of error message at computer startup.

Cause

This behavior of the system can occur if you use an incorrect version of the Command.com file. From my point of view, it’s not so critical cause. It’s a simple cause with more simple solution.

For the detailed description of the cause, go to Microsoft Help and Support page.

Solution

To resolve this issue, replace the Command.com file in the System32 folder present inside the systemroot folder with the same file from another computer that is running windows of the same type.

The systemroot folder is the root folder of your Windows Operating system. It’s present in the drive where you installed your operating system. Open ‘Run’ from ‘Start Menu’ and either type: %systemroot% OR %windir% . Then press the ‘OK’ button. The root folder of your windows operating system will open.

Well, I had this problem in my Windows XP operating system. Then I copied command.com file from my friends computer which was also running Windows XP. Then pasted the file to my system32 folder present in my systemroot folder, i.e. C:/WINDOWS/system32. Then restarted my computer, and the problem had gone away.

Suppose you are using Windows NT and to resolve this problem, you copied the Command.com file from another computer running Windows XP and pasted in your system32 folder. This is a case of different versions of windows operating system. And I am not sure, the above solution will or will not work in this situation. You can try it.

Cheers,

Mukesh