Sorry Phyllis, but you give so little information, I can hardly offer much
help.
I will try to define this in simplified terms. It's easy to slip into
technical answers to your question.
The .NET framework provides a way for programmers to write less code and
produce better programs.
If you are getting an error message from the .NET framework, then you are
running a program on your
computer that uses this technology. The .NET framework has to be installed
by a user of the computer,
and it is not a small or fast installation, so either you, or someone with
access to your computer, has
installed it. This was probably done so that you could run a program
written using it.
It is not easy to tell, by looking, that a program uses .NET (except that it
is much smaller than other
programs
The particular error you are getting is very common, and shows that the
application was not
carefully debugged. The application did something "wrong" and the system
wants to tell it
about the error, but the application didn't provide a way to "listen" to the
system's error message.
(in technical terms, the system "raised an error" and the application didn't
provide a way to "catch" it).
I'm sorry that I can't be more specific. The answer in that a programmer
wrote a program, and you
are running it on your computer (you may not be aware of it. There are
usually two dozen or more programs
running at the same time on your computer.) The programmer used the .NET
framework to write
the program.
Hope this helps,
-- Nick