You’re having problem connecting to a computer in a network, first thing you should do is to PING the computer. Ping is a computer network tool used to test whether a particular host is reachable across an IP network. It is also used to self test the network interface card of the computer, or as a speed test. It works by sending ICMP “echo request” packets to the target host and listening for ICMP “echo response” replies.

Although Ping is useful for network administrators, computer hackers also use Ping to find potential victims on the Internet. By pinging a specific IP address and receiving a response from the IP address, a hacker can determine that something of interest might be there. If you can configure your computer to block ping response, it should heightens the level of security for your computer. I’ve researched on this before but never posted it because thinking that no one would be interested. Yesterday one of our forum member cybercop asked how to block ping, so here it is.
Some routers can be configured not to respond to an ICMP Ping (ping to the WAN port). Like my Belkin N1 Wireless router, it can be set up so it will not respond to an ICMP Ping from the outside. Simply checking the “Block ICMP Ping” checkbox would turn off the ping response.

But if your router doesn’t support blocking ping, there is nothing you can do on your computer because your router automatically respond to ping request.
If you have a direct connection, there are a few ways to block PING. Third party firewall should help you to block ping. I remembered I wasn’t able to ping the computer on a local network when the McAfee Firewall is enabled. As for the built in Windows Firewall, enabling it doesn’t block PING.
Another method to block PING on a single computer is to use IPSec by creating a policy element that will tell the computer to block all the specific IP traffic. The step is pretty long, you can refer to the article written by Petri IT Knowledgebase.
Finally, if you want a simple way to block PING with a click, you should check out Plax Network Suite. Plax Network Suite is an easy to use collection of network tools which give you full control over the internet activity of your computer. You can easily enable or disable Windows Firewall, block all internet traffic and block ping with ONE click.

It even have a port scanner and a visual report of all open TCP/IP and UDP ports and the mapping to the owning application. This can be used to quickly identify unknown open ports and their associated applications.