Windows 7: Recovery of Mirrored Data

I have Win 7 64 bit Pro.
I installed 2 identical disks and set them up to mirror using the Windows 7 option.

I now have a boot problem. It only goes as far as 'Windows is starting'.
Start up Recovery did not work. The report says 'a patch is preventing the system from starting'
System Recovery did not work. Tried all the 10 points I have. All run and then say they have not worked.

I cannot get into Safe mode as F8 fails to work. It just goes to the startup recovery option. Tried lots of times.

So I could reinstall the OS.

However I know this normally destroys all data.

The question is - will it also destroy the mirror data?

If not then how do I get the data from the mirror back to the drive C ?

Any help would be appreciated.

Thanks
Les