this is Microsoft's recomendation on how to fix this sort of error
I am fairly certain it does not matter if the Win 7 DVD is the same version (Ultimate/Pro/Home) as installed on the hard disk when doing a repair to the boot manager
You did not say if Windows 7 on the Hard Disk is 64 bit or 32 bit as replacing corrupt Windows files will require the correct version (32/64).
best of luck
That's correct, all of the x64 disks of Win7 are the same. Same as the x86 disks... they are all interchangeable, IE, x86 Home Premium disk could be used to install Ultimate, and the same is true for the x64 side.
Again, you are also correct in observing that the correct x86 or x64 disk will need to be supplied (ie since the system is x64, you will need any windows 7 x64 disk to use).