SNMP Analysis

Hi,
In the first task of SNMP Analysis lab, we have to find live hosts and I ran “nmap -sn 10.10.10.0/24 --disable-arp-ping” command and it discovered 2 IPs 10.10.10.205 (mine) and 10.10.10.20. But when I ran “nmap -sn 10.10.10.0/24” it discovered 10.10.10.5 host too. I think that it happened because of Windows firewall and I just want to make sure if I am right or not. Thank you very much.