I'm trying to set up a server (Apache) on my computer (fairly new to it). As I understand it, for it to be accessible to other computers, I need to forward port 80. When I try to forward the port though, I get the error: Server IP must be a LAN IP. I noticed in ipconfig that my default gateway is different than my wireless router. My computer is not hardwired, not on WiFi. Furthermore, I do not, at this point, have a static IP. I read that it should still work with a dynamic IP until it changes. Any ideas on what I can do?

I'm using Windows 7 in case it matters.