ping is a computer network tool used to test whether a particular host is reachable across an IP network. It's also simple way to test if your internet connection works.
If you're using XP select:
Start -> Run...
In the dialog box type 'cmd' and press the Enter key.
The black DOS screen that comes up allows you to ping a host. For example type 'ping www.bbc.co.uk' and press Enter.
If it works, you should see three or more lines starting 'Reply from ...'
Close the black DOS screen by typing 'Exit' then press Enter.