To quickly check what hosts on your entire network are up and running without installing any software, try the following command:
for /l %i in (1,1,254) do ping -n 1 -w 1 192.168.1.%i
Where 192.168.1 may be replaced with your appropriate network number.
The screen will scroll through for a couple minutes as it pings each host on your network. When it is complete, type the following command to display the active hosts:
arp -a | find "xx-xx-xx-xx-xx-xx