I use ASUS P5W DH Deluxe motherboard, when trying to setup RAID, I have following problem ...

first step is okay:

You must set the RAID item in the BIOS Setup before you can create a RAID set(s). To do this:

1. Enter the BIOS Setup during POST.

2. Go to the Main Menu, select IDE Configuration, then press <Enter>

3. Select the item Configure SATA As, then press <Enter> to display the configuration options.

4. Select RAID from the Configure SATA As item options, then press <Enter>.

5. Select the item Onboard Serial-ATA BOOTROM, press <Enter>, then select Enabled from the options.

6. Save your changes, then exit the BIOS Setup.

second step is not okay, and I get stuck ...

Then I press CTRL + I during boot as the manual instructs to enter the Intel Matrix Storage Manager Option ROM Utility, in which both of my drives are listed under "Physical Disks." Then I choose the Create RAID Volume, enter a name for it, select RAID 0 (Striped). The next option is to select the disks to add to the RAID, only it is grayed out and disabled for me! I cannot get into the select disks category and therefore I cannot set up the RAID array. What gives? As I said, the two drives are recognized by the main screen of the RAID setup utility, but once I try to create a RAID array it's like they don't exist anymore.