I try it with my laptop on location then if that's OK we reboot the modem, router and test again. For W7 you have to be careful about date, time settings as some antivirus suites drop connections like this on expiration (something I disagree with.)
Then we use system restore to when it worked and finally if that fails we install some USB WiFi stick to see if the WiFi hardware is the issue.
So earlier today I couldn't connect to my wifi due to a disconnected network drive I remapped a drive and was prompted with the message local area connection doesn't have a valid ip connection. I tried to give it a static IP which didn't work. I then unchecked the ipv6 and did the ipv4 setting and retried a static IP still nothing. I the did ipconfig /release the I tried ipconfig /renew and was prompted with unable to contact dchp server and have no idea what to do next can I get some help.