I have not heard of NetSky's causing signal spikes, but a signal spike is exactly what it sounds like a shot of high Voltage high Current, "power", sent into your lan connection, if you did get a signal spike you would have more than likely lost your cable modem also. I would run SFC as mentioned above, uninstall the card throw it in a different machine, if possible, completely unistall it from your current hardware profile then re-insert the card and reinstall the drivers.