Vista 64 Ultimate - Blue Screen then - Boots to Black Screen

After the recent Vista Updates last week i Noticed my PC was freezing. It
eventually Blue screened on me. When I went to reboot it would only reach a
black screen with the mouse pointer available and functioning.

I have tried to enter via the various Safe Mode options but all lead to the
same black screen. I have tried using the repair functions from my orginal
disc but it suggests there are no errors and I can subsequently only get to
the blank black screen with mousey.

I placed all my HDs in a seperate machine running Vista Home Prem 32 and all
were accessible except for the Hd that contaned my Vista 64. It appears in
Computer as a Local Disk but Access is denied. The only way I can the see
data in any capacity is when I attempt to apply security permissions to the
disc. It applies permissions to all but a few files showing that the data is
still on the disc.

Any ideas ? I have previously repaired XP System Hives using the backup
files and aftermarket command line software is there any other way I can
repair this Vista as I need to clarify what if anything I stand to lose from
this volume before I think of reformatting and reinstalling.

I have also disconnected any new hardware and I sadly have no Restoe Points
to work to.