Multicast traffic is actually pretty simple to create with any programming language. If you got python installed here's an example, I hope it works under Windows.

import sys
import socket
from time import sleep

UDP_IP=sys.argv[1]
UDP_PORT=sys.argv[2]
TTL=2
DATA="whateverandever"

sock = socket.socket( socket.AF_INET, socket.SOCK_DGRAM )
sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, TTL)

while True:
  sock.sendto ( DATA, (UDP_IP, int(UDP_PORT)) )
  sleep(1)

Save it to i.e. mcast.py and execute it like this:

python mcast.py <destination> <port>

Change TTL in the script if you whant the traffic to reach further down in the network.