Q:

mt7601u drivers not working ubuntu 16.04

I am using a Wayona USB wireless adaptor and Ubuntu 16.04 has preinstalled the mediatek drivers but suddenly Wi-Fi has stopped working. It shows disabled network. I have all recent updates installed  
this is the wireless info of my system
I have tried restarting the network services, downloaded and installed drivers from this link.
This is the output from running 
lsmod | grep dell 

dell_smm_hwmon         16384  0
dell_wmi               16384  0
sparse_keymap          16384  1 dell_wmi
dell_laptop            20480  0
dell_smbios            16384  2 dell_wmi,dell_laptop
dcdbas                 16384  1 dell_smbios
dell_rbtn              16384  0
wmi                    24576  2 dell_wmi,wmi_bmof
video                  40960  3 dell_wmi,dell_laptop,i915

How should I proceed?

A:

I suspect that you bought the Realtek mt7601u device because the internal Intel device is not working. It is not working for exactly the same reason that the internal device is not working. It is because of this that we see in your paste:
0: dell-rbtn: Wireless LAN
    Soft blocked: yes
    Hard blocked: yes

‘Hard blocked’ usually means that the hardware switch on the laptop is set to disable the wireless radio. In fact, you say:

wifi has stopped working. It shows disabled network. 

There are several things you can try. First, obviously, find and press the Airplane Mode button or switch on the laptop. After doing so, check again from the terminal:
rfkill list all

Is the hard block changed and does the wireless spring to life?
If not, then try unloading one of the three modules that are supposed to translate key presses to action; in your case, turn on the wireless. Try:
sudo modprobe -r dell-laptop

Now does the Airplane Mode button or switch work as expected?
How about:
sudo modprobe dell-laptop force_rfkill=Y

Now does the Airplane Mode button or switch work as expected?
How about:
sudo modprobe -r dell_laptop
sudo modprobe dell_laptop
sudo modprobe -r dell_rbtn
sudo modprobe dell_rbtn auto_remove_rfkill=N

Now does the Airplane Mode button or switch work as expected?
Finally, I suggest that you try a live session of Ubuntu 18.04 as there have been some steps forward in dell-rbtn since 16.04.

