UBUNTU Hardware Enablement Stack (HWE) out of support & rviz segmentation fault

安裝12.04.5 LTS 更新 Hardware Enablement Stack (HWE)後螢幕黑掉，
原來是我加裝的顯卡7V7300GS可能太舊沒有支援。
使用原本主機板上的顯示晶片就可以了。

另外，在更新前使用ROS rviz 執行時會發生的
#rosrun rviz rviz
compiled against OGRE version 1.7.4 (Cthugha)
segmentation fault (core dumped)
也消失了

不過後來rviz又出現令一個錯誤
Ogre::RenderWindow* rviz::RenderSystem::makeRenderWindow(intptr_t, unsigned int, unsigned int): Assertion `false' failed.

我想是之前顯卡的驅動做怪，找到網路上有人這麼做

sudo apt-get purge nvidia-*
sudo rm /etc/X11/xorg.conf # if the file does not exist , then is OK
sudo apt-get install nvidia-common ubuntu-desktop
sudo apt-get install --reinstall xserver-xorg-video-nouveau
sudo dpkg-reconfigure xserver-xorg
sudo reboot

重開機後 rviz is working

python virtualenv packages path not found

I practice to install django with virtualenv in windows.

When i type "django-admin.py startproject mysite", 

it can not import django.core and the error message is    

" from django.core import management

ImportError: No module named django.core"

find the solution from below link

http://stackoverflow.com/questions/8012956/python-django-virtualenv-windows

This is because, it still use the python.exe in default (C:\python27) not the python.exe in my virtualenv (D:\venv\Scripts).

using the ftype to check the Python.file

D:> ftype Python.file

using the ftype to change the Python.file

D:\ftype Python.file = "D:\venv\Scripts\python.exe" "1%" %*