Wifi suddenly stopped working, works with Ethernet cable, works with iPad and iPhone, but not with Sony Vaio laptop. Have spent hours on the phone with Internet Service Provider, who went through all settings and checked everything. I'm using Windows 7 and have McAfee. What could have caused this to suddenly stop working? How do I get it to work again? I have checked my wifi is still on, it still connects to the wireless modem router (D-Link), and at start up has a yellow triangle with exclamation mark inside, then that disappears and says internet is connected (on internet bars icon) but no browsing. Have tried on different wifi connections, with same problem. I restored to the last date I could use wifi and it didn't change anything.... Help please!