cannot ping

I'm unable to ping other computers and so do they.
Can anybody tell me what may be possible ways to ping other systems?
I'd tried by turning off the firewall of both the systems too, but still it showed "distance unreachable".
Please help me, it's urgent.
Thanks in advance...........

 

Is your computer in your local network or in a datacenter? What's the output of

Code:

iptables -L

?

 

Use this link http://www.pingassist.com/ to ping other system...After that test the ping test here http://www.whoisxy.com/ping.aspx at free of cost...

 

Thanks for help.
It's a good help, but I have shifted to linux in which I'm able to do whatever I want.