This is not a TTWin error, this is a name resolution problem. You will receive this error if you enter the host name incorrectly or if there is a problem with your DNS server or your connection to it. Some suggestions that may assist you in resolving this issue are:
Check your are using a valid host name.
Check that you have a Name Server, if you don't you will need to use the Host IP Address instead.
Try pinging your host to see if it is responding.
Try another host name that is known to work.
Check the Host Table on your PC.
If you are still having problems try using the Host IP Address.