Thanks for the code! I just had to add the library Ws2_32.lib and the header Windows.h, works perfectly! Thanks!

I made a list of points:

class CPuntoList : public CObject
{

public:
CPunto* raiz;
CPuntoList();
void Inserta(CPunto* nodo);
virtual ~CPuntoList();
virtual void Serialize(CArchive &ar);
long getSize();
}

The serialize function of the List looks like this:

void CPuntoList::Serialize(CArchive &ar)
{
CObject::Serialize(ar);
long i;
if(ar.IsStoring())
{
ar<<raiz;
}
else
{
ar>>raiz;
}
}

the Punto Class looks like this:

class CPunto : public CObject
{
public:
CPunto();
CPunto(double _x, double _y, double _z, double _zTn);
CPunto *m_pSigPunto; // Pointer to the next point
CGLColor *m_pColor;
void Inicializa();
virtual ~CPunto();
virtual void Serialize(CArchive& ar);
public:
double x, y, z, zTn;
private:
DECLARE_SERIAL(CPunto)
};

Serialize functino looks like this:

void CPunto::Serialize(CArchive &ar)
{
CString str;

if(ar.IsStoring())
{
	ar<<x;
	ar<<y;
	ar<<z;
	ar<<zTn;
	ar<<m\_pColor;
	ar<<m\_pSigPunto;	//	Pointer to next point (Linked list)
}
else
{
	ar>>x;
	ar>>y;
	ar>>z;
	ar>>zTn;
	ar>>m\_pColor;
	ar>>m\_pSigPunto;	//	Pointer to next point (Linked list)
}	

}

Now the question is: When I load about 200 points to the list or even 5,000 points and I save the data to a file using the serialize functions everything works fine, both the storing and the loading. But when I try to save about 12,000 points, there is an error in both storing and loading, it says "Stack overflow." I think because from one function (the serialize function) I call the a serialize function over and over so the Stack overflows... Is that the problem? or what could be the issue? anyways, more importantly, how can I solve it?? Please help!!!!