actually, something like this happened to me some time ago, but the other way around. on my desktop (W7 SP1), hardwired to my router, I lost the internet connection. after using without problems the desktop for more than a year, all of the sudden my ethernet connection had the yellow exclamation mark on it and refused to connect to the internet. no matter what i tried, i couldn't fix this. the only solution was to buy a wireless card. even today i still don't know what went wrong.