root@ubuntu:/# apt-get install --reinstall xserver-xorg-video-intel
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  chromium-codecs-ffmpeg-extra libkeybinder0 linux-headers-3.19.0-15 linux-headers-3.19.0-15-generic
  linux-image-3.19.0-15-generic linux-image-extra-3.19.0-15-generic
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded.
Need to get 0 B/699 kB of archives.
After this operation, 0 B of additional disk space will be used.
E: Can not write log (Is /dev/pts mounted?) - posix_openpt (2: No such file or directory)
(Reading database ... 242228 files and directories currently installed.)
Preparing to unpack .../xserver-xorg-video-intel_2%3a2.99.917-1~exp1ubuntu2.2_amd64.deb ...
Unpacking xserver-xorg-video-intel (2:2.99.917-1~exp1ubuntu2.2) over (2:2.99.917-1~exp1ubuntu2.2) ...
Processing triggers for man-db (2.7.0.2-5) ...
fopen: Permission denied
Setting up xserver-xorg-video-intel (2:2.99.917-1~exp1ubuntu2.2) ...
Processing triggers for libc-bin (2.21-0ubuntu4) ...
root@ubuntu:/#