Nahh, I don't think it is a modified version, it is simply a very old (never recommended) version.
Rethinking about the matter, it is likely that the issue is that the BOOTMGR that is chainloaded from the Windows directory on (hd0,1) tries to load the \boot\BCD from the same partition (while in reality it is in (hd0,0)).
If this is the case the \boot\BCD is still OK, and all it is needed is to *somehow* copy the BOOTMGR from the second partition to the first one.
Possibly with a more recent version of grub4dos we could try a few more tricks, but I believe that version being a very old one it simply misses a number of needed commands.
Now we need to boot to *something* (like a CD/DVD or USB stick).
If I am right and the \boot\BCD is OK there is no need of a windows 7 install disk or of a PE, *anything* that can copy (on NTFS) the /Windows/Boot/PCAT/bootmgr
to root of first partition would do.
We haven't tried to see if any of the files found on (hd0,0) is a copy (renamed) of BOOTMGR:
bootmgr <- this is most probably a "fake" or however not-working BOOTMGR
bootmgr_ <- this maybe is a backup copy of BOOTMGR
BOOTSECT.BAK <- this very likely is a backup copy of the bootsector that
GRLDR <- this is a grub4dos GRLDR (what is actually loaded)
sh4ldr <- this is part odf the spyhunter crap
Again since it costs nothing (at the most it won't work) what happens with:
If the above doesn't work, you need to find an alternative boot media, what do you have available? Any USB stick that you can re-format for this?