sudo apt-get update
sudo apt-get install linux-headers-$(uname -r)
sudo apt-get update
sudo apt-get install build-essential
sudo apt-get install git
git clone https://github.com/lwfinger/rtl8188eu
cd rtl8188eu
make all
sudo make install
sudo modprobe 8188eu.ko
and then I used the following command:

sudo lshw -C network
to get the internal wifi driver file name and then add it to blacklist

sudo -H gedit /etc/modprobe.d/blacklist
and add the following line to the end of the file:

blacklist xxxxx
where xxxx is the internal wifi driver file name.

Restart and Ubuntu should now work with the usb adapter.