I've just spent the last 30 mins trying to log into windows live messenger but i kept getting the error error code 80048820 extended error code 80048439, i searched the internet for a resolution to the problem, but none of them resolved it, however the main theme i came across was the fact it was down to a wireless router, so i logged into my router and restarted it, and immediately logged into windows messenger with no problems, so if your experiencing the same problem, try this first before re-registering all the necessary .dll files.