Exactly, I suspect, that there is still a special "Recovery" partition on the hdd, which contains the needed third party drivers to get the preinstalled Vista x86 runnning again after a crash.
1. Confirmed. No WINNT.SIF file anywhere on the disk. This is a certified Microsoft windows installation disk, not a copy.
2. There is no file named NVRAID, period, on the disk. I even exported the .CAB files and unpacked them using winrar. Nothing.
So, is it obvious that the NVRAID.sys file is still on the hard drive (not loading during installation)?
You should erase this "Vista x86 Recovery" partition and all will be fine.