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The Microsoft Visual C++ 2008 SP1
Redistributable Package (x86) installs
runtime components of Visual C++
Libraries required to run applications
developed with Visual C++ SP1 on a
computer that does not have Visual C++
2008 SP1 installed.
This package installs runtime
components of C Runtime (CRT),
Standard C++, ATL, MFC, OpenMP and
MSDIA libraries. For libraries that
support side-by-side deployment model
(CRT, SCL, ATL, MFC, OpenMP) they are
installed into the native assembly
cache, also called WinSxS folder, on
versions of Windows operating system
that support side-by-side assemblies.
Como o VirtualBox requer o Visual Studio 2003 ou 2005 para as instruções de criação , estou assumindo que elas são do VirtualBox.