trouble installing Python-2.2a1.exe

Tom Good Tom_Good1 at
Mon Jul 23 19:53:03 CEST 2001

"Tim Peters" < at> wrote in message news:<mailman.995680776.21360.python-list at>...
> [Tom Good]
> > I downloaded the Python-2.2a1.exe installer from SourceForge, and
> > verified that the MD5 sum is correct.  When I run it under Windows
> > 2000 Professional [Version 5.00.2195], I get an error dialog that
> > says:
> >
> > 16 bit Windows Subsystem
> >
> > The NTVDM CPU has encountered an illegal instruction.
> > CS:020c IP:0115 OP:0f 00 00 00 00 Choose 'Close' to terminate the
> > application.
> [also Tom Good, later]
> > Sorry, I had thought that this was a problem with the installer, but
> > it really turned out to be a problem with my Windows configuration.  I
> > fixed it.
> Would you please spell out what you changed?  I saw anther report of this
> symptom, a few months ago (w/ a different installer), but no follow-up.  I'd
> like to know how you cured it so we can help the next person who falls into
> this trap.

Searching around for the text of the error message led me to this:

Which gave me the clue that maybe it had something to do with the
command interpreter  I fixed it by going into Control
Panel / System / Advanced / Environment Variables, and changed the
System variable "ComSpec" to point to c:\WINNT\system32\
(it had been set to c:\WINNT\system32\cmd.exe).  Then I ran the Python
installer and it worked fine.  After installing Python, I changed the
setting back to the way it was before.

There may be other work-arounds or ways to address the problem besides
this, but this worked for me.

This link also has some info that may apply.

By the way, the symptom of this problem was that I got the "NTVDM CPU"
error message immediately upon trying to launch the installer.  No
program window ever came up, just the error dialog box.


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