I have windows7 & ubuntu, After several days in shudown position,My system is not booting now. I an not even getting grub for OS selection. I have important data in hard disc How to restore & get important data?
All you need to do is follow the documentation here. https://help.ubuntu.com/community/Boot-Repair
Basically there a few methods, but the easiest is just making a CD with the ISO on it listed on the page. https://sourceforge.net/projects/boot-repair-cd/files/
It is a simple process and should get you back up and running.