uses
IpHlpApi, IpTypes;

procedure RetrieveLocalAdapterInformation(strings: TStrings);
var
pAdapterInfo: PIP_ADAPTER_INFO;
AdapterInfo: IP_ADAPTER_INFO;
BufLen: DWORD;
Status: DWORD;
strMAC: String;
i: Integer;
begin
strings.Clear;

BufLen:= sizeof(AdapterInfo);
pAdapterInfo:= @AdapterInfo;

Status:= GetAdaptersInfo(nil, BufLen);
pAdapterInfo:= AllocMem(BufLen);

try
Status:= GetAdaptersInfo(pAdapterInfo, BufLen);

if (Status <> ERROR_SUCCESS) then
begin
case Status of
ERROR_NOT_SUPPORTED:
strings.Add('GetAdaptersInfo is not supported by the operating ' +
'system running on the local computer.');
ERROR_NO_DATA:
strings.Add('No network adapter on the local computer.');
else
strings.Add('GetAdaptersInfo failed with error #' + IntToStr(Status));
end;
Exit;
end;

while (pAdapterInfo <> nil) do
begin
strings.Add('Description: ' + pAdapterInfo^.Description);
strings.Add('Name: ' + pAdapterInfo^.AdapterName);

strMAC := '';
for I := 0 to pAdapterInfo^.AddressLength - 1 do
strMAC := strMAC + '-' + IntToHex(pAdapterInfo^.Address[I], 2);
Delete(strMAC, 1, 1);
strings.Add('MAC address: ' + strMAC);
strings.Add('IP address: ' + pAdapterInfo^.IpAddressList.IpAddress.S);
strings.Add('Gateway: ' + pAdapterInfo^.GatewayList.IpAddress.S);
strings.Add('DHCP enabled: ' + IntTOStr(pAdapterInfo^.DhcpEnabled));
strings.Add('DHCP: ' + pAdapterInfo^.DhcpServer.IpAddress.S);
strings.Add('Have WINS: ' + BoolToStr(pAdapterInfo^.HaveWins,True));
strings.Add('Primary WINS: ' + pAdapterInfo^.PrimaryWinsServer.IpAddress.S);
strings.Add('Secondary WINS: ' + pAdapterInfo^.SecondaryWinsServer.IpAddress.S);

pTempAdapterInfo := pAdapterInfo;
pAdapterInfo:= pAdapterInfo^.Next;
Dispose(pTempAdapterInfo);
end;
finally
Dispose(pAdapterInfo);
end;
end;