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.
