Perhaps we can repair it via the cmd prompt in the installer disk?
I've been at it all night since my pc has developed this issue, it would appear that either the registry, or textures are FOULED up, i really don't like Vista, so i'd say both.
I know the boot-loader can be repaired via the repair cmd prompt, so im figuring we can trigger something to copy/re-install the textures, or use the Vista-PE disk (that dang disk microsoft made to fix Vista), and try and execute REGedit from it and check the registry, since unfortunately, the installer disk's regedit, only reads the install disk..
Just some ideas for yas, im still at it, if i figure it out, i'll be back.........