Vista - 64-bit Vista installation hangs at end

I have got to what I think is near the end of the 64-bit install of Windows
Vista. It hangs with the black screen which has the version details in silver
in the bottom right hand corner of the screen.

Basically I'm using a separate physical drive to my main XP install, and
I've gone through the teal screens with the Copying files, Expanding files,
...., Completing install, then a couple of automatic reboots occur then in
just hangs on the black screen with the build details as mentioned above.
after half an hour, the screen goes dark and the hard drive ceases all
activity.

I am using :

Athlon 64 3700+ Processor
MSI SLi series MS-7185 motherboard
1 GB DDR-400 RAM
2x SATA 160 GB HD