Not familiar with Deepin but as it is based on Debian, I think you should boot up your Deepin system & run:
Code:
# apt-get install os-prober
# grub-install --target=i386-pc --recheck /dev/sdX
# grub-mkconfig -o /boot/grub/grub.cfg
Replace "X" (in "/dev/sdX") with the drive letter assigned to your main drive (use `lsblk` to list all attached drives & their sizes).
You should probably backup your MBR (to a file called "mbr.bak", located in your current working directory) before doing this:
Code:
# dd if=/dev/sdX of=mbr.bak bs=512 count=1
If everything goes wrong, you can restore it (from a live system) using:
Code:
# dd if=mbr.bak of=/dev/sdX bs=512 count=1
All of this is assuming you are
not booting in EFI-mode.
You should check that you
do not have any files under
/sys/firmware/efi before you follow these instructions.
If you do have files in that directory, post back here for further advice