This problem is probably self made.
I have an Asus mobo set up for raid 0 with two 250gig discs, I also have a third disk that would have been unused as the mobo allows only for raid or a normal setup not both.
My answer was to make a "bodged" raid 0 with only this one disc this works very well under Vista and gives me needed space for backups.
I did not want to dual boot so I have tried to install on this "single disc" raid 0.
The install started as would be expected, I installed the raid drivers
and windows could see the single raid array (I disconnected the working array as I do not want any connection.)
When I tried to install onto this drive the first time, I got the message that windows would not install as the drive was probably not bootable.
When I just tried to replicate the problem to get the exact message I got a different message "Windows could not determine if this computer contains a valid system volume"
Either way I don't come any further, this is however not a great problem as I dont want to do anything that will break the working array.