Have you changed any hardware or installed any new software since you were last able to connect?
Have you double checked that the XP firewall is off & that Mcafee's allowing LW?
How do you have your router set up (UPnP enabled, port forwarded or neither)?
If your router supports UPnP, enable it & then choose the UPnP option within LW's tools > options > advanced > firewall config. If that's not helping, you might have to try port forwarding. Have a look at this site.
PortForward.com - Free Help Setting up Your Router or Firewall
There are a few Draytek routers listed, if yours is one of them you'll find step by step instructions
Don't forget the step of setting up a static IP address if that's part of the instructions. Remember that LW's listening port, port number in the 'manual port forward' box & port forwarded within the router all have to be the same number