My computer has problems keeping my internet connection?

[Daniel]

My computer at random times will "Lose connection", as if the internet has gone down. It usually happens every 40 minutes-an hour, but sometimes happens every 20 minutes. In order to fix it, i have to disconnect from the internet, then reconnect to it.

P.S. My brother is using the same internet on his computer, and it has never done this to him. I have tried using BOTH wired AND wireless connections with the same problem. So I know its not the internet service. I have had this problem with any internet connection i use, wireless or wired connection.

Any ideas on what might be causing this, and how to fix it?
Im using Windows 7. My laptop is about 2 years old (I got it when I start college).

He isn't on a guest network. We're both using the same network.

@adam, It could be it. But why would it only happen for me and not him? I've had this problem for weeks, but he's never had it happen once.