On at least a few laptops, the following is a dependable if annoying workaround.
- Turn off the WiFi with the laptop hardware switch (“airplane mode”)
- Open Start –> Computer –> Manage –> Device Manager –> Network Adapters
- Right-click and disable the wireless adapter
- Wait a bit and verify the OS has completely lost the wireless adapter (by watching the icon in the tray)
- Turn on the WiFi with that hardware switch
- Right-click and re-enable the wireless adapter
- Wait … potentially a couple of minutes for Windows to find the appropriate network, connect, and recognize the route (if applicable) to the Internet
This maneuver is a hassle, to be sure. But it seems to work 100% of the time on some laptops (including mine) and it is much more convenient than rebooting, which is the only other dependable solution.