Hi,

It all started on a night when we had a lightning storm. The power went out once for a second, the computers turned off. Turned back on, everything was fine. Than this happened again a couple minutes later. Turned everything back on... what's this? The outside world can't see the computer when the external ip is trying to be accessed. I didn't change anything, and now I'm trying to figure out what happened and how to fix it. Any suggestions?

Is your problem that you can access the internet outgoing but incoming attempts to initiate a connection fail? If so, then it sounds like your external (WAN) IP address has changed. This is a possibility if your ISP uses DHCP to assign your IP address.

If you are connected directly to the internet you can use ifconfig to find your IP address. Probably you're behind a router or cable modem (which probably includes a router) and you will need to find the router's WAN IP address. If you don't know how to do this (it will depend on your specific router) then you can just send yourself an email. Use "View Message Source" (or some similarly named option) to look at the email headers. The "Received:" line that is furthest down in the email should reveal your (possibly changed) WAN IP address.

To protect your PC from being damaged you should have a UPS and not use it or even have it on during a lighting storm. Power brown outs can damage electronics just as easily as power spikes.

You really haven't explained the problem nor how you connect to the internet. When you reapply power make sure you turn on in order the modem, router and then the PC.
Check the firewall and any services to see if everything is running. You also might want to check the logs too for anything out of the ordinary.