Multiple windows in OpenGL

GLuint l_PixelFormat = 0;

// some pixel format descriptor that I generally use:
static PIXELFORMATDESCRIPTOR l_Pfd = { sizeof(PIXELFORMATDESCRIPTOR), 1,
	PFD_DRAW_TO_WINDOW + PFD_SUPPORT_OPENGL + PFD_DOUBLEBUFFER,
	PFD_TYPE_RGBA, m_BitsPerPixel, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 16, 0, 0, PFD_MAIN_PLANE, 0, 0, 0, 0};

if(!(l_PixelFormat = ChoosePixelFormat(m_hDC, &l_Pfd))){
	throw std::runtime_error("No matching pixel format descriptor");
}

if(!SetPixelFormat(m_hDC, l_PixelFormat, &l_Pfd)){
	throw std::runtime_error("Can't set the pixel format");
}

if(!(m_hRC = wglCreateContext(m_hDC))){
	throw std::runtime_error("Can't create rendering context");
}

wglMakeCurrent(m_hDC, m_hRC);

HDC hDC = GetDC( hWnd ); /* get the device context for a particular window */
/* snip */
HGLRC hRC;
hRC = wglCreateContext( hDC ); /* get a render context for the same window */
/* repeat with hDC2 and hRC2 with another window handle*/

wglMakeCurrent( hDC, hRC );
/* GL calls for first window */
wglMakeCurrent( NULL, NULL);

wglMakeCurrent( hDC2, hRC2 );
/* GL calls for second window */
wglMakeCurrent( NULL, NULL);

void COpenGLControl::UpdateCamera()
{
CSaveRestoreRC c(hdc, hrc);

// Map the OpenGL device coordinates.
glViewport(0, 0, renderingWindow.Width(), renderingWindow.Height());

// Do your other OpenGL stuff here
// ...

// the CSaveRestoreRC destructor will automatically put the correct render context back,
// even if you call other functions. Of course, put another CSaveRestoreRC there too.
}