Make sure you have installed .NET Framework 2.0/3.0/3.5. Also you might need the redistributable visual c++ 2005 or 2008.These are the links for 32 bits OS(x86) and 64 bits OS(x64) download the necessary installers according your PC's OS and if you haven't installed them yet.Microsoft Visual C++ 2005 SP1 Redistributable Package (x86) [nofollow]orMicrosoft Visual C++ 2005 SP1 Redistributable Package (x64) [nofollow]Microsoft Visual C++ 2008 SP1 Redistributable Package (x86) [nofollow]orMicrosoft Visual C++ 2008 SP1 Redistributable Package (x64) [nofollow]Microsoft .NET Framework Version 2.0 Redistributable Package (x86) [nofollow]orMicrosoft .NET Framework Version 2.0 Redistributable Package (x64) [nofollow]This is for either 32 or 64 bits OS. Microsoft .NET Framework 3.5 Service Pack 1 [nofollow]
No. .NET Framework and Redistributable packages act like the brits vet, are stackable. If you have .NET 4.0 you will only run apps that have been made with .NET 4.0, so does Redistributable package.Eastern Front needs 3.5 at least, but I recommend to have 2.0 as well, the 3.5 SP1 updates the 2.0 and installs 3.0/3.5 afaik.