.... The internet connection stopped working, WiFi is not my thing so I ran the trouble shooter and it comes back saying there is problems with the Network Adapter.
Broadcom 802.11n Network adapter....
avast firewall NDIS Filter Miniport ~ this one has the yellow triangle on it.
I tried plugging in a N900 Wireless Duel Band USB adapter - no change....
I trust the wifi is not switched off either physically or via a key-combination?
1. The Ethernet connection and driver has nothing to do with wifi.
2. The Broadcom driver is the wifi driver. But since it is not red or yellow flagged it is likely fine. I find it interesting that the troubleshooter points at it however yet there is no flag on it.
3. The Avast firewall NDIS Filter Miniport that is yellow flagged may have something to do with blocking your connection. Or it may just be another problem you were unaware of which strikes me as more likely. Or it may have been damaged when you tried to install the N900.
4. The fact you tried a N900 Wireless Duel Band USB adapter unsuccessfully would say that the wifi router is at fault (Have you tried connecting with more than one source?). But I somewhat suspect instead it may be your unfamiliarity with setting up a new wifi connection with the new adapter based upon what you have said. It could very well be the Avast app.http://kb.netgear.com/app/answers/detail/a_id/24941http://kb.netgear.com/app/answers/detail/a_id/13205http://kb.netgear.com/app/answers/detail/a_id/1110http://downloadcenter.netgear.com/en/Di ... on?product