I run Ubuntu 14.04.3 LTS and Windows 8.1 in dual boot. Now I am getting the option to upgrade to Windows 10 but I fear that if I upgrade, it will delete Ubuntu from my system.
How can I upgrade to Windows 10 without losing Ubuntu? I have important data and it will take a lot of time to transfer my data to hard disk.
If there is a possible way to transfer my data from Ubuntu to Windows, it will also help me.
Upgrading Windows shouldn't affect Ubuntu, unless you allow the Windows 10 installer to mess with your partitions. If the Windows 10 installer simply changes the Windows partition, it won't affect the Ubuntu partition; that's pretty straightforward.
That being said...if you care about the data that much, you need backups. Not just for this occasion, for ALL occasions. I've heard it said: There are two types of people: Those who have complete, regularly updated backups of all their important files and software...and those who will. Anyone who has experienced the sickening horror of a failed hard drive that contained the only copies of their files, will understand the black humor of this saying.
No hardware lasts forever. Buy an external drive, they're very cheap these days; $70 can get you a good 1TB USB 3.0 drive. And back up your important files. If your computer got hit by a sledgehammer right now, would you pay $70 to have all your files back? I thought so.
Back Up Your Files.
During the upgrade process Windows will likely tell you whether it's going to modify just its own partition, or also other partitions on your disc. If it only modifies the Windows partition nothing with your bootloader or Ubuntu partition should change.
You can transfer your files from Ubuntu to Windows right from your file manager. If you're using Nautilus, select your Windows partition in the sidebar under "Devices" and move your files to your Windows desktop as you would into any folder.
