I don't know the name of the compiler, I have installed Visual C++ 2005 Express edition, and my OS is XP.
What do u mean by object files?
I think there are only two types of files, one is header and other is cpp.
I have created two files,one is post.cpp and the other is main.cpp, in my program.
look at this test program.
#include <iostream>
using namespace std;
////////main.cpp/////
int main()
{
cout <<"My test program";
int a,b=4,c=3;
a=add(b,c);
cout <<a;
system("pause");
}

#include <iostream>
using namespace std;
//////////post.cpp//////////
int add(const int x,const int y)
{int res=x+y;
return res;}

Error 1 error C3861: 'add': identifier not found