I've built a windows app on .NET 2.0. I have a few users that run it without
issue. One user reports that it immediately pops up the standard windows
window that reports:

<program> has encountered a problem and needs to close. We are sorry for the
inconvenience.

What does this possibly mean ? How can I trace the problem?

NB. I have a "run in debug mode" option which writes to a debug log file but
even that is not generated.

Search microsoft.com for the error text, something like

  "encountered a problem and needs to close" "sorry for the inconvenience"

You will find a lot of reading.  The fact that only one user shows the
symptom suggests that his computer has a problem.  I don't think your .net
app has anything to do with it.  It is likely a failed 3rd party component,
spyware, etc.  I suggest starting with a comparison of installed programs
between the trouble user's computer and another that does not have the
problem.

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