How to fix the MBR for Windows 7?

Solution 1:

Try EasyBCD. EasyBCD is an advanced GUI application that makes it easy to modify the Windows bootloader and the entries in it.

Choose BCD Deployment, and write the MBR.

enter image description here

Solution 2:

I have solved this with a Boot-Repair disk (I put it on a USB flash-pen, but one can burn it on a disk if necessary). I had used the program mainly to repair the grub in linux, but it has an option to repair the MBR.

So, boot into the Boot Repair disk/usb, and check "Restore MBR" (instead of "Reinstall GRUB").

enter image description here

It works fine, the normal boot in Win7 is back in place.

Solution 3:

Check here: grub says unknown file system. what do I do?

Follow this: https://help.ubuntu.com/community/Boot-Repair