Dual boot with Grub Ubuntu 16.04 / Win 10 broke when Win 10 automatically updated to Version 1803 in August, 2018. Windows overwrote the Master Boot Record and the Grub menu has disappeared. Ubuntu HDD partition still exists. Windows 10 Ver 1803 works. How do I repair the MBR, retain dual boot functionality, and boot from the existing Ubuntu partition? I want Windows to be the default, Ubuntu to be my secondary boot option. Can I use Visual BCD to accomplish this? Is there a Grub2 option? Thanks in advance for your help!