i am new to ubuntu, i am installing LXLE 14.04.03 (64bit) on a Lenovo G50-30 preinstalled windows 8.1 updated to Win10 Home. I carried out the install with Secure boot disabled and Bios/uefi optimised for other OS. The multiboot options will only allow ubuntu to run, it declares windows to have boot problems. The ubuntu file system has mounted the wrong partition as windows, so i cannot see windows files. I believe some of this problem is because it is installed as Legacy OS.

Question: To boot installation media (DVD but same for USB?)i have no option but to set BIOS to load legacy first, only way it doesn't load windows, so how could i install in UEFI mode as is reccommended in posts i have read?

I have read scores of posts here and think i could unmount the empty hda5 partition and mount windows as hda4 in etc/fstab But i think i need to edit grub to get windows to load from multiboot screen? Is this correct?

Easier to reinstall? but only if i can correctly identify the partitions. I went with alongside windows but perhaps now that partitions have been made i could try to go with "something else" but scared of losing Windows.

I can run Windows by loading UEFI first in BIOS. Disk manager shows partition order but i have a 1mb partition (created as its legacy/BIOS installation i understand) it is marked as Primary, not sure if i should count that when calculating hda? number.

If i understand correctly i just need to allocate partitions for the OS & Swap drive if i try "something else" option? Is the swap drive likely to be the 3.89 gb partition just before Ubuntu partition or there is a 13.19 GB "recovery partition" which has been created at the end (last) of the drive.

Thanks for any help sorry for long post Tony.?

  • I have discovered rufus and the art of making and hopefully loading UEFI USB drive so i could start again. If i do that will it detect the old installation and auto select partitions etc. Should i uninstall ubuntu somehow or format or remove the partitions already created? Thanks ... – Tonymandala Jan 14 '16 at 14:39

I'm left guessing at some critical details you haven't provided. As I understand it, your Windows is installed in EFI mode, and presumably you've installed Ubuntu in BIOS mode. If so, this was a mistake; it's almost always best to install all your OSes in the same boot mode. In the case of an EFI-based computer with the first OS installed in EFI mode, it's almost always best to leave the Compatibility Support Module (CSM; aka "legacy boot support") disabled. See this page of mine for more on why this is the case.

Given your situation, re-installing Ubuntu is one reasonable course of action. Re-installing is overkill, but since you presumably haven't yet customized it much or created many files in Ubuntu, it's a fairly simple way to do it. Be sure to disable the CSM first, which should get the installer to boot in EFI mode. (If you have problems booting the installer with the CSM disabled, chances are you prepared the boot medium incorrectly. The page I just referenced covers this in more detail.)

Another option is to install an EFI-mode boot loader for Linux. There are many ways to do this, but the two that are likely to be easiest are:

  • GRUB/Boot Repair -- The Boot Repair program can automatically install and updated version of GRUB 2. In your case, you'd need to boot from an Ubuntu emergency disk (like your installer), but it must be booted in EFI mode to install the EFI version of the program. Also, although this tool usually works, there are occasions when it doesn't, so it's a bit of a "leap of faith" to use this approach.
  • rEFInd -- My rEFInd boot manager can be installed in Windows; or you can try it by using the USB flash drive or CD-R image to be sure it works, then boot to Ubuntu and install the PPA or Debian package. You may need to disable Secure Boot, though, at least at first. (You can re-enable it later.) If you install rEFInd in Windows, be sure to also install the EFI driver for the filesystem on which your kernel resides (probably ext4fs).
  • Hi Rod Smith, thanks for your help. I think i have given all the info in my question, what are the "critical details" that you need to know? As i explained i installed in Legacy/BIOS mode as that was the only way to boot from my installation DVD. I know that was not ideal and have now discovered that i can make an EFI usb boot media (see my note). The questions i needed answering are in my comment, will new installation detect existing ubuntu partitions ? should i uninstall or format? I will look at your page and do more research, its first thing Sunday morning here in France! I'll get back.. – Tonymandala Jan 17 '16 at 10:23
  • Hi @Rod Smith, I have read your page on CSM/UEFI very clear thanks. I have now edited the fstab file and have access to the ntfs partitions. I'm now considering trying to edit GRUB rather than re-installation. Are you saying that If I were to stay with my current Win/UEFI & Ubuntu/BIOS combination that editing Grub is not an option? (“GRUB cannot switch boot modes.”) but I could use rEFind which could load both types? I could try the (“Boot Repair utility, but this is best done from an EFI-mode boot”) in CSM mode? Or not? Does this install an EFI loader or edit the existing one? – Tonymandala Jan 17 '16 at 12:33
  • At the moment I can set UEFI mode and Windows is fine, no sign of Ubuntu, good for other users of the computer. I can set CSM mode and have Ubuntu legacy loader. Is it possible to edit/fix the Windows option? I suppose I am asking, is it fundamentally possible for the legacy loader to issue an instruction to load Windows installed in UEFI ? If not I must reinstall or use rEFind. Thanks for your help – Tonymandala Jan 17 '16 at 12:35
  • No, a BIOS-mode GRUB cannot be an EFI-mode Windows. To get dual-booting working from GRUB, you must harmonize the boot modes. The easiest way to do that is to install an EFI-mode GRUB, which in turn effectively requires an EFI-mode boot of Linux. – Rod Smith Jan 17 '16 at 23:38
  • Thanks a lot @Rod Smith i understand it now. Start again now i know the rules! Hey not bad this OS very zippy compared to Windows and customizable, i'm hooked. Cheers. – Tonymandala Jan 18 '16 at 20:50

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