Hardware Error: A cable might be unplugged. Check the physical connections.
Request Timed Out: Communication problem though the network and client computer is present. There was no reply from the Host computer. No echo response was received. This could be due to network traffic or a router problem.
Destination Host unreachable: The client is not available on this network. Check the DNS servers / settings.
TTL expired in transit: TTL stands for ‘Time to Live” – this value actually determines the maximum time the IP packet may ‘live’ on the network without reaching its destination. This means the number of hops to the destination exceeds the time to live. You can fix this by using the -i switch along with the ping command.
For more information on the PING command, type PING /? in the command window.