Unable to find any valid windows partitions on this computer...

Yesterday I spent a couple of hours recovering my wife's PC from a boot error; "Ox...", which occurred after a power outage.
This was eventually achieved by using the Windows 7 Recovery disk from NeoSmart.

This morning my computer present a similar message on startup; Boot error status Oxc0000098, without there having been a power outage.
I thought the Windows 7 Installation disk Repait utility would fix this. It gave me a message that the Windows version on the computer was incompatible with the Installation disk (despite having been loaded from that disk).
Given my success yesterday I thought using the NeoSmart recovery disk would be the answer.
However, on getting the RD to boot and applying the Repair option I was presented with the following message.
"Unable to find any valid Windows partitions on this computer..."
I opted to take the command prompt alternative and blundered around for a while. This revealed that the partition sector did not have an end mark. I tried unsuccessfully to rectify.
I tried the MBR code write option, then rebooted but the same boot error reappeared.
I tried rebooting from the reboot alternatives; Sata PS and PM plus UEFI, all without success. I then retried the Windows 7 Installation disk repair utility again. This time it worked.

The only thing I can think that caused this was something I did when after I had downloaded EasyBCD yesterday (before discovering it did not fix boot errors). At some stage when I was trying to use Easy BCD it asked if I wanted to create a partition. I did not realise that in doing so I would possibly corrupt by boot directory. I would appreciate someone speculating on what I may have done.

Why did the recovery disk not work given its sole purpose is to fix such problems?