Hi!
Let me start from the beginning.
My HDD's partition table is GPT. I was using Win8.1 and Ubuntu 14.04.2 LTS in dual-boot.
Now that I've installed Win10, grub is gone.
So, I have to fix/reinstall grub. I tried "boot repair disk" -method. But, "recommended repair" option is not easy. It asks me to run some command in terminal.
I'm kind of familiar with basic terminal commands, but I'm no expert.
So, I'm kind of afraid to step forward with this.
See, I used MBR before and had no trouble. But my last HDD died after I converted it to GPT and did the same (fix grub after reinstalling Windows).
Experts, please help me to fix/reinstall the grub on this GPT table (with a safe method, so I won't lose any data or my HDD).
Thanks in advance.