Ever since I updated some of our company laptops (Sony Vaio E-Series) and a desktop to Windows 8.1 they seem to have a problem with connecting to the server domain on wireless and one of them on LAN when they boot up. They connect to the router but somehow forget to log on to the domain as well so then network drives, MS Outlook and printers etc do not work and they have to reboot which usually rectifies the problem but one of the laptops does not want to ever reconnect to the domain unless it is wired in. ?