Setting up own virtual server on xp laptop

[Calibra]

Have setup a virtual tekkit server 3.1.2 on my laptop.....worked really well. Unfortunately after shutting down and starting again the next day, i got a server cannot be found when running the tekkit launcher. After much hair pulling and research on the internet i got it working again, had to restart server laptop several times....

I am using a dlink dir655 router and using the port forward settings to link to the laptop virtual server.

I have read that the IP address i am using on the router is the IPV4 address (local IP address)

Then i read that this address changes each time the pc is restarted, so i tried manually setting the local ip address on the laptop.....although it said the router was connected, the internet would not work.

Obviously i am not doing it right and maybe have gone down the wrong route. But i did have it working perfectly, so there must be a way to keep,it like this.

Hope someone can help me.

Many thanks

Ps is tekkit 3.1.3 any better and can worlds from 3.1.2 be copied to 3.1.3 server folder......