If you have installed more than one Operating System in your PC. For example, you have Windows 7 & Ubuntu installed and suddenly you are unable to boot to any of the OS. If the error similar to given below appears:
A very simple solution for this would be to boot into the live CD/USB and run Boot Repair
Boot Repair PPA
Boot into Live CD/USB.
Type the following in terminal(one line at a time)
sudo add-apt-repository ppa:yannubuntu/boot-repair sudo apt-get update sudo apt-get install -y boot-repair
Run Boot Repair
Type in terminal
Click the Recommended repair button
enter image description here
After the process is finished close everything.
This should solve your problem.
5,748 total views, 1 views today