Issues with Windows 7 Installer seeing hard drives?

[Vapor1000]

So i picked up 2 300gb velociraptors on the FS/FT here this past weekand have formatted them, filled them to capasaty, read the files on the drives, deleted the partitions and reformatted them as NTFS to test the drives before i installed eather as a system drive.

I then went into installing the 1st Raptor into my mini.
All looked to be going well, bios saw the drive. Then PC Booted to Windows 7 DVD install disk and took me to the install. Windows would then not recognize the Raptor and told me i had no hard drives (raptor was only one plugged in) to install or partition to install windows on.
After trying various SATA connectors/Cables/Power connectors even loading SATA drivers, no go. Then i plug in the other Velociraptor that i bought from the pair. and Voila. it see's the raptor. Went back to try the 1st Velociraptor again, Nothing. Still no drive in the windows 7 Installer.

Anyone think of any logical reasons for this?

Both drives are fully usable in a computer that already has windows 7 installed on another drive.But only 1 will allow me to install windows 7 to it?

 

[Vapor1000]

Update: Problem Solved, but dont quite understand why.

After i deleted the NTFS partition on the drive, windows installer saw it fine.

This would make sense if it were consistant, and i could simply blame it on windows inability to create its 100mb system partition for system files and other emplaments of destruction. but both drives had the same partition created on them.

1 NTFS, the other NTFS. Both took up the full volume. Neather marked as an active partition, or anything. Just 2 drives both formated with standard NTFS partition.

Its so annoying when you fix something, but dont fully understand why what you did fixed it :-|