Two things come to mind -
Firstly, have you installed the SATA host adapter driver for Vista? It should be supplied with the mobo (or download it).
Secondly, does the mobo support 150 or 300MB/s SATA drives?
If the former, and the drive is 300MB/s, you can use the jumper block adjacent to the SATA interface connector on SATA 300MB/s drives to force the drive into SATA 150MB/s mode (for use with older SATA controllers that only work with SATA 150MB/s drives).
SD