Im certain someone will correct me, but i have had and seen other with same problem.
Try to install with only minimal stuff
2gb of ram, not 4 put 4 in after install (shouldnt matter but it does)
make CERTAIN that your installing it on the SATA 1 port.
Myself and two others could not get vista to install one any port but number 1
I had to remover ram and two other HD before vista would install. Go vista working put ram and everything else back in and all was happy.