This happened twice, because I blanked the PC again (put it back to factory settings) after I gave up trying to solve the problem. I paid special attention. The wifi is found and officialised during installation. It all works after installation. I'm offered the updates that are available since my DVD was made. I download them. When I restart the PC theres no wifi, just the empty "fan" in the status bar. I go into the network menu, into wireless. My connection details are still there, but absolutely no way to connect as far as I can see. On the home screen, when restart, theres a message saying "you are offline", or something close to that. If nobody has any answers, I'm going to try reinstalling again, and not updating again till I'm a bit further forward with this.