'WiFi does not have a valid IP configuration' message has started showing up on my laptop after upgrading to Windows 8.1. It happens periodically and I can't definitely say it happened immediately after the upgrade, but it did NOT show before the upgrade. The Troubleshooter solves the problem, but it is an annoyance! Using a Dell Inspiron E1505 laptop--old but workable! Any ideas how to prevent this?? Thanks!