Newbie having issues after installing nvidia drivers

[tek_heretik]

kubuntu was working great until i tried to install drivers for the geforce 8400 PCI. thats when things went wonky.

The proprietary nVidia driver 'unlocks' GPU features that Nouveau most likely doesn't utilize, in turn causing the CPU and chipset to work even harder, robbing the rest of the OS of resources, it's kind of like dropping jet plane parts in a propeller plane and expecting great results.

[Buddlespit]

my windows are still locked in the top left corner, with no min/max/ close option. and chromium and firefox wont go fullscreen

Kwin isn't running. Press ctrl+alt+F1 and log in, then:

$ sudo service lightdm stop
$ sudo apt-get update
$ sudo apt-get dist-upgrade
$ sudo apt-get install kde-window-manager
~at this point, if it tells you that it can't install because of a dependency issue or a configuration issue, come back and tell us about it~
$ sudo service lightdm start

[dtr]

You received the 331 driver because you have the xorg-edgers ppa activated. I have it installed with no problems but that might not be the case for you. I would suggest you login to synaptic, go into software sources and un-check http://ppa.launchpad.net/xorg-edgers/ppa/ubuntu then reload, then completely remove everything nvidia, and reinstall nvidia-current.
If I remember correctly, to get to software sources in synaptic, you have to click settings, repositories, other software. (you may need to install software-properties-gtk).
I am pretty sure the nouveau driver is install by default. This is what to look for in synaptic xserver-xorg-video-nouveau or just search nouveau to see if it is installed.
Hope this helps.