I presume from your post that you have Vista installed and running on some hard drive as the boot device, and that you have then installed two additional Samsung drives and used the mobo utility system to configure them as a RAID0 array for use as data storage - not as a boot drive. The result is that Vista has detected the existence on a new storage resource (the RAID0 array) but recognizes that it does not have the necessary driver loaded into itself to be able to use that array.
The driver you need should be part of the software on a CD that came with the mobo. Read the mobo manual for this. The usual way this works is that you now place the mobo's CD in the Optical drive and run some Utility Installation menu system that allows you to choose what drivers need to be installed into Windows Vista. There will be a driver you can choose to install for using RAID arrays operated by the mobo disk controllers. Install that, and probably you will need to exit the installation utility and reboot your machine for Vista to recognize the change and start using the array.