Hello! I appreciate your interest my problem! Thanks!
I have a kali linux installed in my Sandisk usb drive, which i use for booting kali on live usb persistence on my laptop.
All was going fine, until I updated my kali by 'apt update', then,'apt upgrade' and lastly i typed 'apt full-upgrade'. After the update was complete, i shut down the laptop. The next time I booted kali linux from my Usb pendrive in live persistence mode, the keyboard stopped working, but my mouse which i use with the touchpad, was running fine. Thinking of what to do, i used the virtual keyboard of kali linux from the universal accessibilities menu, and updated my kali from the terminal again with the same commands I mentioned above. After doing that too, the keyboard was not working.Any help will be appreciated.

Not sure I can help with exactly your problem, however perhaps you should post the hardware specifications for your laptop as well as the version of Kali you started with and what you were trying to upgrade to. One strategy you could consider is to download a full ISO of the intended Kali version you wished to upgrade to as opposed to trying an upgrade command. Is that a possible option to consider? And then you can see if the keyboard now works with a fully up to date, live distribution?

Keyboard not working. You forgot to mention if this is kernel driver issue or X issue.

does the kali wiki have an official method for adding persistence to usb, or how did you achieve that?
did you run the upgrade in the same machine as where the keyboard misbehaves?

Yes sir. I used the correct method for installing usb persistence on my usb drive of 32 gb. Then all was goibg fine. And i ran the upgrades in the same machine as where the keyboard misbehaves. In fact, the keyboard does not work at all. Although, i can adjust the brightness and volume of the kali system properly with the keyboard with the F(1-10) keys, the other keys do not work. I appreciate your reply!

It looks like one of the updates has caused the problem.

I would advise that you reinstall the original Kali and install the updates one or several at a time (you can install multiple if they look non-hardware related) in order to determine which one is the culprit.

My laptop is HP OMEN 2017 version
. I am thinking of re-installing the ISO file as a last resort option. Thnx for your help.

I believe we covered both Kali and text-speak in your other thread:
https://www.linuxquestions.org/quest...0/#post5827524

...where you said you weren't going to use Kali, received several requests to not use text-speak any longer, and were advised strongly against mixing/adding repositories. Seems we've come full circle, doesn't it?

I just copied the original repositories of kali. And i did not mix any repositories after I came to know about mixing repositories as a bad option from you. Before you instructed me on not mixing the repositories, and before I posted the previous thread and before i mixed the repositories, I updated my kali linux on my usb pen drive and then, when i rebooted the system, i observed that the keyboard was not working. And thought to update it again by typing "apt update" and then "apt upgrade" in the terminal with the help of a virtual keyboqrd as my mouse was working perfectly. I then observed that it was gonna take 12 to 12 hours. So then i googled up why was i getting a very slow speed. From there, i came to know about mirrors. Then i opened sources.list file, and then, i switching to mirrors. As i found myself unable to do that, i posted a thread of LQ. Then, after coming to learn that mixing up repositories is a bad idea, i switched to the original repositories. And then, as my keyboard was still not working, i posted a thread here in the HARDWARE section. As you also mentioned of posting threads at their appropriate place. Thank you.

...and we also mentioned about NOT USING KALI, too.

Sir, do you have any ideas regarding this Issue? I will highly appreciate your help in it and will provide you will all the information that you will want. Thank you.

You were given them, yet ignore them. DO NOT USE KALI, period.

Again, as you've been told, it is for advanced users only, and only then really useful to do network security/pentesting. And, again, you can install any of the tools/modifications that kali has, on any other version of Linux. You keep ignoring this advice. You said in your other thread that you understood this, and claimed to only be a beginning user. Yet here we are again.

Again: Kali isn't meant to be used as you're using it. You (again) messed with your repositories and caused a system problem. If you keep ignoring the advice you've been given, there isn't much point in posting questions, is there? You've again damaged your system due to not knowing what you're doing and messing with repositories, on a version of Linux that's above your skill level. If you want things to work again, the best advice is not use Kali. If you insist upon doing it, then you're going to have to reload your system, and start again.

Did you do what I advised in my post above?

I did not reinstall kali linux yet. I am going to do that as my last resort to solve this problem. Do you any idea on which packages dealing with the input should i reinstall?

When i posted the previous thread, i got the solution to why the packages weren't installing. It was not because the repositories got mixed up, but it was because i had forgotten to add the word "deb" in the beginning of the 'sources.list' file.
And when i added "deb" in the beginning of the 'sources.list' file, I was able to download the packages. And my keyboard had stopped working before I changed the repositories.