The next thing I would advise is to perform a repair install with that amount of corruption.
A repair install doesn't affect personal stuff or installed programs.
However, for that you would need a Win 7 x64 Pro install disk and your COA sticker key if it is still legible.
If you don't have a disk, if you private message me your address, I can send you a couple (one spare).
There is an alternative and that is to register on the
www.sysnative.com forum and open a thread where they have Windows experts who can resolve when sfc /scannow reports corruption it is unable to fix by using something called FRST which scans and produces a log of whatever is wrong.
The expertise that is required to use this tool is because of subsequent scripts that are used.
There's one other thing you could try if the hardware is the same on the Backup machine and that is to create a system image of that one onto external media as well as a System Repair disk and restore the Main machine with that.
Anyway, let me know what you decide.