0

the drive partition screenshot There is win7 64 on my internal hard disk(type: dynamic, and that is why I need to install Ubuntu on a external drive). I have installed Ubuntu 16.04.1 on an external hard disk(type:basic). During the Ubuntu installation, I chose "something else" and installed the Ubuntu to dev/sdb (I shrank 50G bytes from the external hard disk, and let it unallocated first on window 7), chose dev/sdb/boot for grub boot loader's location. The installation was successful.

I rebooted my laptop. It can't get into either operating system. I tried boot repair disk, and chose to installed the grub boot loader at the same place "dev/sdb/boot", (It seems that boot repair disk edited the boot loader file on the internal hard disk for win7 ), then I can get access to Ubuntu, but not win7. fixed this problem by editing grub.cfg (change insmod ldm into insmod part_msdos ). I can get into both operating system by choosing the start memu with the external hard disk plugged in.

Now the problem is I can't start the win7 without the external hard disk. The error message is "missing operating system" pop up.

How can I fix this problem? Thank you!

I have checked this answer https://ubuntu-mate.community/t/installing-ubuntu-mate-15-10-on-an-external-hard-drive-and-keeping-internal-hdd-the-same/4748, but didn't figure it out.

larry
  • 21
  • 2
    I do not know if grub can even boot Windows in dynamic partitions. Normally grub chain loads to the Windows Partition boot sector, with with dynamic the partition boot sector is inside the dynamic partitions. Best just to remove the dynamic partitions, but you have to use Windows tools. If 4 partitions or less relatively easy to do. You always install grub to a drive like sda or sdb, never to a partition. If you reinstall Windoes boot loader to sda, then you should be able to choose what to boot from BIOS. – oldfred Oct 07 '16 at 23:35
  • Thank you for your reply.

    I have uploaded the disk partitions screenshot. Can it be converted to basic partitions? I have not Win 7 installation DVD and don't want to lose any data on the drive.

     – larry Oct 08 '16 at 07:33
  • I searched on the internet, and failed to find a solution.

    Now I can't reinstall grub boot loader anymore by boot repair disk. If the external drive is not plugged in, boot repair disk can't fix the "missing operating system" problem. If it is plugged in, the laptop will boot directly to start menu "choose ubuntu or windows 7".

     – larry Oct 08 '16 at 07:47
  • It is easier to only have 4 partitions to convert. But conversion software may make extra partitions logical. Microsofts policy is that there is no undo on dynamic partition, only full backup & redo drive. You still need full backup as major conversion always has risks. http://askubuntu.com/questions/482768/changing-windows-dynamic-disk-partition-to-basic-partition-and-not-the-full-driv and: https://ubuntuforums.org/showthread.php?t=2325331&p=13492758&viewfull=1#post13492758 – oldfred Oct 08 '16 at 13:52
  • Thank you. There are many applications installed on win7 now. I can't take the risk. I also tried disk genius to repair the mbr. It didn't work either. – larry Oct 15 '16 at 09:33
  • You still need backups, and still should be able to install Ubuntu to external drive, but must use Something Else so grub2's boot loader get installed to external drive. During partitioning screen at bottom be sure to choose drive that is external in combo box. Shows combo box: http://askubuntu.com/questions/274371/install-on-second-hard-drive-with-startup-boot-option Does not highlight drive change but other sceens: http://askubuntu.com/questions/312782/how-to-install-ubuntu-on-separate-hard-drive-in-a-dual-boot Links are older versions, but process for Something Else is same. – oldfred Oct 15 '16 at 13:47

0 Answers0