Ubuntu – OS-Prober doesn’t show the Windows 7 partition

12.04system-installationuefiwindows 7

I'm having a problem installing Ubuntu 12.04 on my ASUS UX31A alongside Windows 7; I tried to launch os-prober in my terminal and the only option I get is:

/dev/sda5:Windows Recovery Environment (loader):Windows1:chain

while Windows 7 (mounted on dev/sda3) is not shown.

This is what I see in my Disk Manager in Windows 7:

C: basically is the partition with Windows system's file, while the D: one is for data), while this is what I see when I launch GParted:

May it be because Windows is installed on SSD? How do I know that? Is it safe if I proceed with the installation for computers with UEFI, SSD and HDD? I'm not sure that's my case.

Best Answer

You are using MS-DOS partition table created by Windows 7, and the maximum allowed primary partitions are 4. There are no extended partitions on your system. So when you select "Install along side windows" it tries to create a primary partition and fails.

You should make a new partition table like I've done on my HDD.

My partition table with /dev/sda1 as primary and /dev/sda2 as extended partition.

My partition table with /dev/sda1 as primary and /dev/sda2 as extended

Related Solutions

Ubuntu – Where to install boot loader on a Zenbook Prime

I struggled with the same problem for quite a while, but found a solution now.

The first thing to know is that the Zenbook Prime uses a UEFI-boot mechanism and not a BIOS-based one. The second thing is that the disk is formatted using a GPT partitioning scheme and not the older MBR (Master Boot Record) based one. This is the reason why there is an EFI System Partition (ESP) on /dev/sda1 on the Zenbook.

The boot-loader should be installed on the EFI partition (/dev/sda1).

Also you need to boot your Ubuntu-disk or USB-stick in UEFI-mode (as you did), since otherwise the installer will apparently be confused and install GRUB to the MBR instead of the EFI partition (it seems to me that the installer should be smarter and detect what kind of disk we have, regardless of how the installation medium was booted, but maybe there's a technical limitation somewhere?).

Finally as a workaround it is also possible to add a custom entry to GRUB which points to the right EFI file.

First do sudo blkid and look up the UUID of the EFI partition (/dev/sda1)
Do sudo gedit /etc/grub.d/40_custom
Add the following entry to the file:

menuentry "Windows 7" {
insmod part_gpt
insmod ntfs
insmod search_fs_uuid
insmod chain
search --fs-uuid --no-floppy --set=root 20B1-C9F3
chainloader (${root})/EFI/Microsoft/Boot/bootmgfw.efi
}

Where you replace "20B1-C9F3" with the UUID you looked up in step 1.

Save the file and then run sudo update-grub2.

After rebooting you will see your new entry which should work now.

If you want to remove the other broken GRUB entries from the menu you can easily do it using the grub-customizer program from the repos.

12.04 Dual Boot UEFI Windows 7 and Ubuntu – Fix GRUB Entry Issue

Find where the windows bootloader resides by mounting the efi partition:

sudo mount -t vfat /dev/sdx1 /mnt/efi/

And search for bootmgfw.efi. Then, find the UUID of the drive:

sudo grub-probe --target=fs_uuid /mnt/efi/EFI/Microsoft/Boot/bootmgfw.efi

Add this UUID to /etc/grub.d/40_custom:

menuentry "Windows x86_64 UEFI-GPT" {
    search --fs-uuid --no-floppy --set=root UUID
    chainloader (${root})/EFI/Microsoft/Boot/bootmgfw.efi
}

Finally run update-grub.

Best Answer

Related Solutions

Ubuntu – Where to install boot loader on a Zenbook Prime

12.04 Dual Boot UEFI Windows 7 and Ubuntu – Fix GRUB Entry Issue

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