Okay, here's an odd one.
As a note, we've been suffering some bad thunderstorms in this part of the UK recently.
I had a guy call me today, who I visited, said to me that during a thunderstorm last week, he was using his computer, when he saw a 'spark' (I'm very unsure about this!), and since then his internet doesn't work.
So, looking at his machine (Compaq Tower, running Vista), and his router, I deduced that the problem was on his computer (we replaced all cables and the router, and my laptop connected up just fine, via an ethernet cable - his desired connection method). When looking under device manager, there were no Network Adapters listed (in fact NW Adapters was missing altogether). I restarted the machine, scanned for hardware changes, no joy. I thought that maybe there had been a power surge during the storm and it had fried his Ethernet port (as it carried some power, and was, indirectly plugged into his telephone socket, via the router.
I fitted a new PCI Ethernet Card to replace the MB port, and hey presto, it worked! Managed to get a few bits downloaded, then.... the connection dropped out. Couldn't get it back, although the card was showing in Device Manager. I restarted the machine, and now, under device manager, we are back to square one. I.E. NO Network Adapters shown at all. The card, and the switch I have it plugged into are showing lights, but the computer has totally lost the card again. It's not listed i the Networking section of Vista OR Device Manager.
I have scanned for hardware changes again, to no avail.
Any ideas on what may be causing this strange behaviour?