I have a cable modem for my computer. I also have a wireless router for my brother's laptop. Just yesterday, the internet was going haywire. It would work for 5 seconds and then the icon of the 2 computers on the bottom right of the task bar says Local Area Connection: A network cable is unplugged. It would continuously do that and i couldn't use the internet properly. I called Optimum Online to ask what was going on. They said it was a router problem. They said that something triggered the firewall in my router and that was causing the internet to go haywire. Ive tried resetting the router, ive tried turning everything off, and i tried a full computer virus scan. No viruses were found. After restarting everything, it still didnt work. The only way i can get the internet to work is if i only use the modem. The problem with that is that my brother cant get internet service on his laptop without the router. Does anyone know what i can do to fix the router problem? I dont know how to disable the firewall. I have a D-Link router. The model is Dl-614+. Thanks in advance.

uninstall the Firewall so that all you are using is the Windows Firewall. Check other security such as antispyware and antivirus stuff, particularly if free or cheap.

How?

How do i uninstall the firewall for my router. I'm not sure where to find the firewall for the router. I don't even know what its called.

I connected the Ethernet cable directly to the modem and now the internet works for me but wireless connection is not possible. I tried to access my D-Link routers IP at 192.168.0.1 but its not working. Every time i enter it, the page never loads. It just says that this page cannot be displayed. Nothing else. All other websites work fine. Just that one. I'm pretty sure that i could disable the firewall if i could access that site but i dont know how to anymore.

If it is a Windows firewall, you should not have to remove it, but you can disable it in Control Panel ->Security
If it is any other firewall, you can delete it in add or remove programs, or sometimes in programs by clicking on the firewall named, and then clicking delete.
Still others have a temporary "stop" or temporary disable when you click on the program icon on the desktop.

I dont know how

I dont know the name of the firewall so i cant disable or uninstall the firewall. i dont see anything in add/delete programs that seem similar at all to routers or firewalls for this situation.