Windows 7 No internet access, firewall issues

My internet access keeps going out. The laptop is still connected to the router but my wireless connection says no internet access. I have to disable windows firewall then got to the wireless internet connection status and click on diagnose. It then resolves the problem and gives me an error message that says Wireless Network Connection does not have a valid ip configuration. It fixes the problem and I am connected with access to the internet. After 15 to 20 minutes I get the error again and I have to repeat the process to get internet access.

I have tried going to windows firewall to add an exception for Mozilla to access the internet but Windows firewall will not allow me to add an exception for this or any other program.



I am using Windows Home Premium 7

Dell Insiron N7010