I'm in the USA and have a raspberry pi 2 and 4 usb adapters. 1 of which was sold with the raspberry pi 2, another that I bought based on online reviews saying that it worked (plug-n-go) with linux and the Raspberry Pi, and also 2 other devices. All of them locate the available wifi-hotspots and show their signal strengths, but none of them will actually connect, even though I've put in the password properly. Raspbian doesn't deliver any failure message, any success message, or any report of any type after I key in my password into popup that asks for it. The only think that happens after I type in my password and hit okay is that the popup disappears. No internet connection.
So, I don't think this is an issue with a USB WiFi adapter. It seems to be something going on with Raspbian (Debian Jessie) ... or perhaps a rare hardware failure on my RPi2. Is there a configuration file I should edit? Should I try another operating system or rebuilding from scratch Raspberry Pi 2? I'm at a complete lose as to what the problem is. I've used both a desktop and a laptop with Linux (Kubuntu and Ubuntu) to connect to this password enabled wifi spot, but the Raspberry Pi 2 fails. I'm looking for any suggestions that you think might be helpful.
PS- I've already tried the diagnostics from BASH, running
lsmod and looking at their hardware, and following the standard troubleshooting to get the usb WiFi adapters to work. They are finding the signal strengths of all the WiFi hotspots, but none of them can actually connect. So, I have yet to use this RPi2 with wifi.
# Please note that this file is written to be used with dhcpcd.
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'.
iface lo inet loopback
iface eth0 inet manual
iface wlan0 inet manual
iface wlan1 inet manual
The connection is through a Dlink Wireless Router using standard WEP security. There is no captive portal. Windows, Ubuntu and Kubuntu have all been using it successfully.
New Troubleshooting Information just added
I downloaded and then installed Ubuntu-Mate-15.10.1 onto the Raspberry Pi 2. Both HDMI sound (and wifi adapter) worked perfectly and effortlessly immediately after installation.
I also downloaded and installed the very latest version of Raspbian [ 2016-02-09 ] Both HDMI sound ( and wifi adapter ) continued to fail, as before.
So, this is definitely Not a Hardware problem with my Raspberry Pi 2. It's certainly an issue with Raspbian, the operating system. Since everyone from Britain and Australia seem to have no problem with HDMI sound (or wifi adapters) using Raspbian, I wonder if this could be a regional incompatibility issue or some sort of hardware blockage by region?