Open a Terminal (Applications → Accessories → Terminal) and type the command: lspci

Check to see the hardware is recognised if it is then the section called “Check for driver”

If your device is not displayed then there may be a hardware problem. Ensure if it is PCMCIA or PCI that it is inserted correctly.

Open a Terminal (Applications → Accessories → Terminal) and type the command: sudo lshw -C network

If there is a driver listed then see the section called “Check device is on”.

Set up NDISWrapper (the section called “Using Windows Wireless Drivers”).

Many wireless network devices can be turned on or off. Check to see if the device is turned on by opening a Terminal (Applications → Accessories → Terminal) and type the command: sudo lshw -C network.

If it is turned on then see the section called “Check for a connection to the router”.

Open a Terminal (Applications → Accessories → Terminal) and type the command: iwconfig.

If there is an entry that says ESSID="" then see the section called “Configuring WPA support.”.

If the ESSID for our router is shown there may be a problem with ACPI support. Boot the kernel with the pci=noacpi option.

Open a Terminal (Applications → Accessories → Terminal) and type the command: ifconfig.

If there is an IP address shown see the section called “Check DNS”.

From the Terminal enter the command: sudo dhclient if_name where if_name is the connection listed earlier.

If you receive a message that says bound to xxx.xxx.xxx.xxx then see the section called “Check DNS”

If not then reboot the system.

Open a Terminal (Applications → Accessories → Terminal) and type the command: ping 82.211.81.158.

Now type the command: ping www.ubuntu.com. If you get a response from the both then see the section called “IPv6 Not Supported”.

Type the command: cat /etc/resolv.conf. If there is no nameserver listed then contact your ISP and find out your primary and secondary domain name servers. Once you have this information see the section called “Connect to a wireless network”.

IPv6 is supported by default in Ubuntu and can sometimes cause problems.

To disable it, open a Terminal (Applications → Accessories → Terminal) and type the command: gksudo gedit /etc/modprobe.d/aliases.

Find the line alias net-pf-10 ipv6 and change it to read alias net-pf-10 off.

Reboot Ubuntu.