I am running Windows 7 Home Premium (64 bit) on a Dell Inspiron 560. I am using a DI-524 D-Link wireless router. I have an Acer Aspire One Net Book running Windows XP Home it is equipped with an internal wireless network adapter. I can connect/communicate with router and access the internet with no problems whatever. However, when I connect an external wireless network adapter e.g. Alpha AWUS036H I cannot get a connection when I disable my internal network adapter. I have also tried the Trendnet TEW-424UB USB external wireless network adapter and the symptoms are exactly the same.
If I leave home and use another Wireless point of access I have no trouble connecting using the external adapters which means the problem is confined to my personal home network.
I have removed and reinstalled my router, and the network adapters drivers
etc. I have uninstalled my Norton Firewall and and disabled my Windows firewall to no avail. I have removed my WEP security features and tried to run it open with no improvement. I have connected the external network adapters on a neighbours computer running XP to see if I could connect to my home network. That didn't work as well.
Bottom line is I simply cannot get an external wireless network adapter to work with my router. Yet my internal netbook adapter connects with no problems at all.