MSVC stands for Microsoft Visual C++. It is a Windows program development
tool that was sold seperately and as part of Microsoft Visual Studio. More
recent versions are refered to as Visual C.NET and Visual Studio.NET.
MFC stands for Microsoft Foundation Classes. They are a set of variable and
code definitions for utilizing various Windows interface elements (windows,
command buttons, menus etc) in Visual C++.
The 31 is connected to the runtime version number.
Error message is connected to a common runtime library that is used by many
programs developed using Microsoft Visual Studio and or Microsoft Visual
C++. The message would not nessesarily indicate the operation or absence of
a malicious program.