Wifi does not connect

[John]

You could try to set up wireless manually.

Check Wireless Interfaces:
iwconfig

Check if Wireless Interface is Up:
sudo ifconfig wlan0 up

Scan for Available Networks:
sudo iwlist wlan0 scan

Create a Configuration File for the Network:
sudo (nano or vim) /etc/wpa_supplicant.conf

network={
ssid="your_ssid"
psk="your_password"
}

Connect to the Wireless Network:
sudo wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant.conf

Run the following command to request an IP address from the DHCP server:
sudo dhclient wlan0