Ubuntu 18.04 keyboard and mouse not working at login screen

EDIT: just ask me info and i will give it to you. but someone pleas help me. i just cannot format this system. i did a lot this time to make it workable according to my work environment.please "

i am on my windows laptop now, THE ISSUE IS IN MY DESKTOP UBUNTU 18.04. i know there are tons of duplicate questions for this and yes i tried around 20 of them and none or nothing or no command is working.

i installed virtualbox and vagrant . all was working fine.

went to sleep . woke up next day. i mean three days back and started my pc with only ubuntu 18.04 installed . reached to the login screen. keyboard and mouse not working at all. restarted couple of times . nothing.

so i checked and checked for hours online.

went to recovery mode and then to root shell. tried doing sudo apt update sudo apt upgrade sudo apt update --fix-missing sudo add-apt-repository ppa:graphics-drivers/ppa *** this gave error.

cannot add PPA: 'ppa:~grahics-drivers/ubuntu/ppa'. ERROR:'~graphics-drivers' user or team does not exist. I got this same user or team doesnt exist error on many commands. no resolv.conf file found.

***** one of the questions even had answer to purge nvidia-* which i did and then said to do sudo add-apt-repository ppa:graphics-drivers/ppa and then it game the same error. cannot add PPA: 'ppa:~grahics-drivers/ubuntu/ppa'. ERROR:'~graphics-drivers' user or team does not exist.

******rebooted the pc.....with init 5 and i was able to login.

***** but now after i login and the account open.....the keyboard and mouse again not working.

**** now its working only for login and mouse mouse before login only.

***** recovery mode console or terminal is getting of no use.

Solution 1:

this is now i solved my issue.

1. reached the root shell and logged in by pressing shift key then selecting advanced option.
2. pressed ctrl + alt + f2/f3/f4/f5 .it asked for login details but nothing worked. gave me this error: ERROR : ****** incorrect details. pam_nologin(8)
3. ctrl + d to close root shell and then click clean then dpkg then network and back to root . this time it worked ctrl + alt + f3.
4. asked for login details and this time it did not give me this error: ERROR : pam_nologin(8) kind of error. i was able to login to user terminal.
5. as i had purged my nvidia drivers. i did these things :

6. sudo add-apt-repository ppa:graphics-drivers/ppa sudo ubuntu-drivers devices sudo ubuntu-drivers autoinstall #this installed nvidia-418 for me on its own. sudo apt-get update --fix-missing sudo apt-get install xserver-xorg-input-all sudo apt-get update && sudo apt-get upgrade -y sudo shutdown -r now this is to shutdown and restart.

IT WORKED. i was able to login to my system and then still the keyboard and mouse was working and i checked the graphics card info. it was the latest driver. dont know what had happened before. but this small weird error took my three days and good two nights.

Solution 2:

maybe it is just because of Xserver module lost，I fix it by this： Ctrl + Alt + F1 into the tty mode and

 sudo apt install xserver-xorg-input-all