Q: Lubuntu 15.04 live (with 6gb persistent) don't boot after installing Intel and nvidia drivers Before I intall them everything was normal. Now pc stuck at blue lubuntu boot screen.
I am using 8 gb USB drive to boot
My hdd died that's why I'm using USB drive to boot my pc (hdd unplugged)
Intel dual processor 2.0 ghz
Nvidia 8400gs
2 gb ram

A: I might need some more info, but here is what I know on how to fix this:
During the boot logo, press ctrl + alt + f1 and login with your user name (UNIX user name, not the greeter user name) and run sudo apt-get purge <insert driver package name here>. This should clear the drivers and fix the computer.

A: I got it!! There is no possibility to install updates and drivers on live systems. I installed full system on my USB drive and I am using fully updated system with drivers
