Installed Windows 10. Can't boot into Linux anymore.

[fuzzybabybunny]

Yeah, I saw this coming. This is the first time I've worked for UEFI so I'm wondering if anyone could point me towards a good, structured tutorial on how I can boot back into my Linux (ElementaryOS Luna / Ubuntu 12.04 LTS) install?

I'm upgrading from a Windows 7 install that just used GRUB to select which OS to boot into.

Hopefully I don't have to re-install my Linux since that's where I do all of my work.

 

[pcgeek11]

Boot off a linux live disk. Mount your linux drive and then reinstall grub.

This is with Ubuntu, but should get you going in the right direction:


https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows

 

[fuzzybabybunny]

Boot off a linux live disk. Mount your linux drive and then reinstall grub.

This is with Ubuntu, but should get you going in the right direction:


https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows

If I'm using UEFI should I even be using GRUB?

 

[FrankRamiro]

If I'm using UEFI should I even be using GRUB?

Good luck,if you can dual boot Win 10 and Ubuntu you're my hero as long you post detail on how you achieved it,but i think Win 10 wont let you dual boot Linux! i tryed it before, i could achived good results with Win XP but win 10 not a chance in my PC's, good luck

 

[Jodell88]

Good luck,if you can dual boot Win 10 and Ubuntu you're my hero as long you post detail on how you achieved it,but i think Win 10 wont let you dual boot Linux! i tryed it before, i could achived good results with Win XP but win 10 not a chance in my PC's, good luck

While I don't use Ubuntu, I have Windows 10 and Arch Linux dual booting.

 

[FrankRamiro]

While I don't use Ubuntu, I have Windows 10 and Arch Linux dual booting.

Why don't you post how you do it,that would be a great help.

 

[Red Squirrel]

I find it's too much hassle trying to dual boot, I would put one of them in a VM at least you can run both at same time and you're not messing with the MBR of your master OS. I find the newer versions of windows are very picky about the partitioning/booting sequence and UEFI adds another wrench in mix I prefer not to mess with it.

If you absolutely want to dual boot do it on two separate drives. Set Linux as primary and Windows as secondary and Grub will pickup the windows one and you'll get it in the menu.

Not saying it wont work to dual boot on same drive I just find it's not worth the hassle.

 

[mv2devnull]

If I'm using UEFI should I even be using GRUB?

Yes.

Windows puts its boot loader into the EFI system partition.
Linux puts its boot loader (GRUB) into the EFI system partition.
The UEFI loads boot loader from the EFI system partition.

The UEFI has a list of boot entries in nvram, on motherboard. You should be able to invoke UEFI's boot menu to see the list. Windows installer sets its entry as first&default. It can even erase "competing" entries from the list.

If the latter has happened, then an entry must be added, either with Live distro that boots in EFI mode, or from Windows.

 

[fuzzybabybunny]

Ok, so I managed to get it working:

I've got a 500GB SSD and it's arranged like so:

sda1: system reserved
sda2: windows 10 boot + programs (200GB)
sda3: windows and linux shared storage (160GB)
sda4: elementaryOS boot (14GB)
sda5: elementaryOS storage (100GB)

I had ElementaryOS Luna installed when I first installed Windows10. It wiped out Grub. I then used an ElementaryOS Freya live disk and installed a clean version of Freya in the place of Luna. After successfully creating partitions using GParted and installing Freya, Grub started right up listing the two OS'es just fine.

No repair of Grub was necessary. I've read that Freya supports UEFI natively.

 

[brianmanahan]

I find it's too much hassle trying to dual boot, I would put one of them in a VM at least you can run both at same time and you're not messing with the MBR of your master OS.

agreed - with performance overhead of only a few % in virtualization now, i just install 1 OS and then use VMs for all the other ones

 

[ninaholic37]

agreed - with performance overhead of only a few % in virtualization now, i just install 1 OS and then use VMs for all the other ones

I know that Dosbox runs like a 386/33MHz on my laptop and running Dos in VMWare is around 5 times slower than that, so I boot into FreeDos natively, at 800MHz. The difference in speed is around 20-100x (2000-10000%).