For Start > Run > cmd
or
Start > (All) Programs > Accessories > Command Prompt
ping 127.0.0.1
External ping resources:
BBC 212.58.224.35
Dagens Nyheter 62.119.189.4
Expressen 193.180.57.70
Nordea 195.215.15.167
IPCONFIG
ipconfig /all
ipconfig /flushdns
ipconfig /registerdns
ipconfig /release
ipconfig /renew
netsh int reset c:resetlog.txt
netsh int ip reset log.txt
netsh interface ip reset log.txt
netsh int reset all (I used to use this one, as it was easiest to spell over the phone!)