no graphical login / lightdm killed

[KisteBecks]

hi,

i tried to reset my lightdm configs with:

dpkg --force-all --purge lighdm
apt-get install lightdm

but now sudo /etc/init.d/lightdm wont do anything besides show the boot
messages on tty6. theres nothing on tty7.
theres also no error even if lightdm is started manually without the init scripts.
im currently running "x" with startx and gnome-terminal as first application in ~/.xinitrc.
any idea how i can get the problem solved so that i can login again normally?

cant even move windows around

[Argenteus]

Try

dpkg-reconfigure lightdm

Also, did you misstype and mean sudo apt-get install? If not, try installing again with sudo, you need root access to install applications.

[KisteBecks]

yes i do work with sudo when required, in this case i just didnt write it down.
sadly the reconfigure did not create a chance

this was missing:

/etc/lightdm/lightdm.conf 
[SeatDefaults]
allow-guest=false
user-session=ubuntu
greeter-session=unity-greeter

quesiton: why did apt not install the file a second time after a purge?