So, I have 512GB SSD laptop in which I had windows pre-installed. recently, I installed ubuntu in it for dual boot. Both the OS were working perfectly. Suddenly today I was booting into windows and faced BSOD error. I tried multiple ways to solve the problem but could not. Laptop would go into "Preparing Automatic Repair" and BSOD on the next screen. My Ubuntu was working fine.So I tried to mount the windows partition and EFI partition using "mount" and realized that both the partitions have a similar directory named /EFI and it has the Windows Boot Mgr. So I tried to copy the directory in EFI partition to the windows one. And in doing so I removed the directory in the EFI partition. And now my laptop directly goes to BIOS and doesn't even show any boot menu. I am booting into the system using a bootable Ubuntu flash drive. Doing so, I can see all my partitions perfectly. So, I am quite sure it is not a hardware issue. Can this be solved or do I have to install both the Operating Systems from scratch. Thanks!!
If you are lucky and haven't destroyed the boot environment too much, you should be able to get by without total reinstallation:
- Create a Windows boot media, or use a Windows recovery disk (if you have one)
- Repair the Windows boot as described in How to Run a Startup Repair in Windows 10
- This will recreate the EFI partition, but with only boot into Windows
- Use the Rescatux Disk to restore Grub and the Linux boot.
If all goes well, you would recover both the Windows and Linux installations. In the future, it is safer to modify boot data using a utility, rather than doing dangerous partition modifications manually.