Blank Screen/Command prompt on Ubuntu/Window 8.1 daul boot toshiba laptop

Finally I was able to resolve the issue. Following is the summary

• Issue #1 I believe sudo apt-get install xserver-xorg-video-intel was installing incorrect drivers for Ubuntu 12.04 LTS. (Expert opinion is sorted)

Solution: Sudo apt-get install xserver-xorg-lts-precise

• Issue #2 The following errors we observed.

  "Failed to fetch http://security.ubuntu.com/ubuntu/dists/precise-security/Release"

Based on the following thread poor internet connection might have contributed to the issue. Thus went to local library to mitigate the issue.

• Issue #3 There might have been some package management issues, suggest by this post.

Made the following changes to sources.list file to mitigate issues #3.

sudo nano /etc/apt/sources.list

The following line were added at beginning of the file

deb mirror://mirrors.ubuntu.com/mirrors.txt precise main restricted universe multiverse
deb mirror://mirrors.ubuntu.com/mirrors.txt precise-updates main restricted universe multiverse
deb mirror://mirrors.ubuntu.com/mirrors.txt precise-backports main restricted universe multiverse
deb mirror://mirrors.ubuntu.com/mirrors.txt precise-security main restricted universe multiverse

All in all the Windows 8.1/Ubuntu 12.04 LTS stared to work as expected.

Thank you community for sharing suggestions. Hopefully someone else can benifit from these notes.