Hi all
A couple of days ago I hit an error with a dual boot setup which existed for some months. The dual boot entry was missing and I could not repair/refresh/reset with any install disk. Chckdsk and sfc /scannow from the other partition and from the install disk repair command prompt did not help. The dual boot partition was locked. EasyBCD did not provide a solution either.
After a lot of searching I did come across this you-tube and it provided the solution.
To repeat :
Start-up with install disk and commence with "repair your computer" and follow to command prompt.

X:\sources> bootrec /scanos
X:\sources>bcdedit /export D(the failing partition): \BCDBKP01
X:\sources>ren D:\boot\hcd hcd2.old
X:\sources>bootrec /scanos
X:\sources>bootrec /rebuildbcd

I hope that showing/linking a solution here might be handy for someone in trouble.