Okay. Let’s kill the persistent process. Execute:
ps aux | grep -i apt
This will produce a list of processes. If there are any apt in there, that’s the reason. You can go ahead and “shoot them all in the head” by typing:
sudo killall apt apt-get
Then re-execute:
sudo rm /var/lib/dpkg/lock-frontend
sudo apt install -f && sudo apt autoremove
Once this is done, go back to the build-essential sequence. 
Unbelievable. It stopped them. There were about 100 apt’s. But as soon as I typed your next two commands it started again!
Did any of the commands go through or did it immediately produce the error?
The first kill command executed, but the next two immediately produced the error
Okay, let’s kill everything that may try to interfere, including dpkg and then try to reinstall the driver without any initial apt commands:
sudo killall apt apt-get dpkg
sudo rm /var/lib/dpkg/lock-frontend
cd ~/Downloads
sudo dpkg -i --force-overwrite ./wireless-bcm43142-dkms_6.20.55.19-1_amd64.deb
Once that is done (hopefully), execute the following:
sudo apt autoclean && sudo apt autoremove & sudo apt update
Please let me know if you get any error message - so that we can initiate the repair command.
Can I copy and paste that or do I need to type it one line at a time?
Yes, you can copy paste everything, but one line at a time. Alternatively, you can attach them in a single line, but separate each command with the && symbols.
In case this doesn’t work again, do the following:
sudo killall apt apt-get dpkg
sudo rm /var/lib/apt/lists/lock
sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock
And try again. This should remove any and all locks.
Wow! You have quite the upgrade there!
First, I see the bar progress below, which means that somehow an installation process is still undergoing in the background. Is the bar progress advancing?
No, the bar processis not advancing. Have to type twenty characters.
Then I would recommend to close that terminal and start a new one. This one is overloaded and frozen. Your issue mainly began due to version miss-matches. So, we’ll need to go to try a full system upgrade first.
Open up a new terminal, after you closed the previous one and type in:
sudo killall apt apt-get dpkg
sudo rm /var/lib/apt/lists/lock
sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock
sudo apt upgrade -y
If it doesn’t produce an error, you have a massive list of files that need to be upgraded. So, it may take a while.
Looking good so far.
Good! I’ll be preparing for a meeting, so I apologize in advance for my upcoming delay.
Once the upgrade is done, then you can reboot and check if you have any WiFi (sometimes this helps). If not, then do the:
cd ~/Downloads
sudo apt install build-essential
sudo dpkg -i --force-overwrite ./wireless-bcm43142-dkms_6.20.55.19-1_amd64.deb
sudo apt install -f
And then give it another reboot. Hopefully, this time you will not have issues with database locks.
Ok, got through it all successfully. Rebooted. My heart fell when there was no network symbol in the bottom. No connection. SMH. No locks, tho. The only connection that shows is the wired one I am hard-using. I am typing on my other laptop.
Okay, since you were able to do all the updates, perhaps this last step will solve your issue. Open up a terminal and execute:
sudo apt install broadcom-sta-dkms
Then reboot and re-check.
I thought you had given up on me. That did not work, altho it did say the install was successful. I’m wondering if I can’t add a profile and force it to pick up the router?
Hey @Stacey!
No, I don’t give up! I’m a bit too hard-headed!
However, I do find it interesting that the two main driver setups didn’t work. When you open up the Network Settings, does it still only present the Wired option?
Yes, the wired option is the only one.
Out of curiosity, is Secure Boot enabled in your BIOS? There are quite a few cases where it hinders additional modules - and disables WiFi and Bluetooth (I helped a couple of people here in the forums who had that exact issue). Please check it out.
If it’s disabled, then we’ll go on ahead and re-install the overall driver - in case it was disabled to begin with (we now have all the firmware files installed).