When Windows firewall is on (as the default settings) in Windows XP computer, it will not respond to ping requests, so obviously you can’t ping to the particular computer. You will be getting ‘Request Time Out’ reply from the destination, even though its connected and accessible in local network. The reason behind is, ICMP packets which used in ping command is blocked in default firewall rule in Windows XP. This guide shows how to enable ping in XP by enabling ICMP echo packets.