Why can I boot Windows only with grub2 chainloader?

  • Phpdna

    When I updated my dual boot (Windows and Linux) PC my grub menu.lst file was deleted and I could no longer boot into Windows or Linux.

    Finally I have succeeded in installing grub2 and I can boot both OSs but I cannot repair my Windows OS with the recovery console.

    I've still some problems with grub2 and Windows 7 but I expected to repair it from the recovery console.

    I assume the mbr of my Windows disk is ok because it works with the chainloader from grub2.

    The problem is I cannot boot Windows without the chainloader or grub. It even failed to write a new boot sector because Windows cannot detect the filesystem. This happens to me with the bootrec.exe /FixBoot command. I also cannot command bootrec.exe /RepairBCD it gives the same error.

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    Related Question

    windows 8 + gentoo uefi grub 2 dual boot
  • puchu

    I've bought a new computer with asus sabertooth 990fx motherboard (well known asus ami bios which can use uefi properly) and installed windows 8 using uefi and gpt to play wine-not-compatible games. Disc now contains partitions:

    1. ms efi boot - 100M
    2. ms recovery - 100M
    3. ms root - 100G
    4. unallocated space - 400G

    I want to install gentoo by adding partitions mentioned in handbook and no touching MuStdie:

    1. ms efi boot - 100M
    2. ms recovery - 100M
    3. ms root - 100G
    4. grub2 efi boot - 200M
    5. linux swap - 16G
    6. linux root - 30G
    7. linux home - 350G

    I am new to uefi booting. I was using bios + grup-pc + mbr on old computer. It is possible in this case to use only one bootloader thats why I was using chainloader to boot windows (see handbook)

    Specific question: Is it possible to use two uefi bootloaders(ms + grub) in different partitions?

  • Related Answers
  • puchu

    I've succesfully installed grub 2 to the second uefi partition and both two loader works via manual (site is not working now. use google cache to see). The main trouble for me was to create bootable usb flash with uefi. But when I've done I saw uefi power => uefi + gpt + grub 2 + gentoo + windows 8 = works perfect

    But then I saw that each loader is less then 50 megabytes, moved two loaders to the first efi partition and dropped the second efi partition. It works still perfect ^__^