If you type something like:
explorer http://www.codeproject.com
in an Explorer window or Command Prompt, then the Internet browser you use will open :). You can use it like this in code:
#include <stdlib.h>
main()
{
system("explorer http://www.codeproject.com");
}
in C++. Or:
System.Diagnostics.Process.Start("explorer","http://www.codeproject.com");
in C# :)