Unable to connect wifi ubuntu 14.04 LTS HP Pavilion Network driver rtl8723be

You need to install the driver using dkms. If you build it from the lwfinger git, it stops working after kernel upgrades.

I packed the same driver as DKMS and added it to a ppa. Install it this way:

sudo add-apt-repository ppa:hanipouspilot/rtlwifi
sudo apt-get update
sudo apt-get install rtlwifi-new-dkms linux-firmware

and reboot.

Quite often, the weak signal is a symptom of the antenna wire being connected to connection #1 on the card when the default driver is expecting to see the signal at connection #2. Of course, you could open the laptop and switch the wire or you could install a newer driver that permits antenna selection at the driver level.

Please obtain a temporary ethernet connection by ethernet, tethered or whatever means possible. Open a terminal and do:

wget https://github.com/lwfinger/rtlwifi_new/archive/rock.new_btcoex.zip
unzip rock.new_btcoex.zip
cd rtlwifi_new-rock.new_btcoex
make
sudo -i
make install
echo "options rtl8723be ant_sel=2"  >  /etc/modprobe.d/rtl8723be.conf
exit

Reboot.

Whenever Update Manager installs a later kernel version, also known as linux-image, after the requested restart, you must recompile:

cd rtlwifi_new-rock.new_btcoex
make clean
make
sudo make install

Reboot and your wireless should be working.