Google search results.Why can't I find info on "Missing MBR-helper"?
https://www.google.com/search?q=missing ... 20&bih=894
There is a chance you have a corrupted mbr on sda.
Windows 7 made a mbr.
EasyBCD's boot loader probably made an mbr.
Grub4dos config made an mbr.
Usually I would use Windows recover to let it rewrite the mbr for Windows.
Get Windows booting OK with it's boot loader.
That seems to be what that did./sda_mbr.bak>/dev/sda' gets Windows 7 booting flawlessly again.
Got Windows mbr back and working correctly.
Try Grub4dos config again using default settings.