Program Test;

uses Windows, WinInet;

function ReadFileFromURL(URL: PChar; Buffer: Pointer): DWORD;
var
    BytesRead : DWORD;
    hInternet, hURL: WinInet.HINTERNET;
begin
    Result := 0;
    hInternet := InternetOpen('Test', INTERNET_OPEN_TYPE_PRECONFIG, nil, nil, 0);
    if hInternet <> nil then
    begin
       hURL := InternetOpenUrl(hInternet, URL, nil, 0, INTERNET_FLAG_RELOAD or INTERNET_FLAG_DONT_CACHE, 0);
       if hURL <> nil then
       begin
          while InternetReadFile(hURL, (Pointer(DWORD(Buffer)+Result)), 1024, BytesRead) and (BytesRead = 1024) do
                Inc(Result, BytesRead);
          InternetCloseHandle(hURL);
       end;
       InternetCloseHandle(hInternet);
    end;
end;

var  
    Html : string;

begin
    SetLength(Html, 10000);
    ReadFileFromURL('http://google.ru', @Html[1]);

    if Pos('Поиск информации', Html) > 0 then  // Если нашли строку в коде страницы, то...
       MessageBox(0, 'Всё зер гут!', ':)', 0);
end.