Go to the windows update page and find what was installed.
Remember that we can not avoid technical jargon entirely but any DRIVER from Microsoft and that could do it in.
About a week ago, my Asus laptop (Asus Notebook U50F Series) downloaded an automatic update from Microsoft/Windows. When it later restarted, it showed that I was connected to my home network, but that the laptop no longer had an internet connection. My wife's mac notebook didn't have any problem with the net, neither does the PlayStation.