#include <winsock.h>
#include <stdio.h>

void __fastcall TForm1::Button1Click(TObject *Sender)
{
WORD wVersionRequested;
WSADATA wsaData;
wVersionRequested = MAKEWORD(1, 0);
int err = WSAStartup(wVersionRequested, &wsaData);
if(err == 0)
{
char hn[1024];
struct hostent *adr;
if(gethostname((char *)&hn, 1024))
{
int err = WSAGetLastError();
Beep();
};
adr = gethostbyname(hn);
if(adr)
{
  char *LocalIp = new char[15];
  sprintf(LocalIp,"%d.%d.%d.%d",
  (unsigned char)adr->h_addr_list[0][0],
  (unsigned char)adr->h_addr_list[0][1],
  (unsigned char)adr->h_addr_list[0][2],
  (unsigned char)adr->h_addr_list[0][3]);
  Label1->Caption=LocalIp; //Выводим IP адрес
}
}
}