The BT support "technicians" advice is utter rubbish.
First what do you mean can't connect?
Is it that they know they are not connected wirelessly to the router or is it that when opening the browser they get "page cannot be displayed" error?
Until this is verified you are working in the dark
Obviously if you go over there with a laptop, tablet or mobile phone and can connect wirelessly to the router and open a web page, then the problem is on the pc.
Windows XP has a regular history of the tcp/ip stack registry entries becoming corrupted for no good reason. Vista also sometimes suffered, but have never I come across the problem on 7 or 8
Try downloading a small utility called WinsockXPFix.exe which is still available although 9 years old.
A Google search will find multiple download sites. This will reset it for you.
And of course you can always leave it on the pc for them to run again if a problem reoccurs.
You can do it manually using the netsh commands.
Run a Command Prompt as admin and type "netsh winsock reset catalogue" and press return. Reboot and the connection will be fine if that is the problem.
I've also come across firewalls that have become corrupt and totally block access for no reason.
Norton was/is famous for it. Only option is to uninstall the firewall.
Hope this may help.
Edited by deleted (Mon 21-Jul-14 22:35:38)