The problem:
When someone in my household connects to the internet through wireless, our internet goes down for a few minutes and then eventually comes back up. My desktop and my uncle's desktop are connected to our router through a wired connection. If im the only one home, i never DCed, it's when my cousin tries to use her laptop to connect wireless that the problem happens. This becomes a bigger problem when we have guest over and everyone has their smartphones trying to connect to the internet, the internet just goes to shit and keeps disconnecting.

My uncle and I are both using dynamic IP addresses no static (actually all the devices are), and DHCP is enabled on the router. Our provider is comcast and currently a cisco router. I've been thinking of updating the router's firmware, but we had a linksys router before this and problem was still happening, switching routers didnt do anything.