Revised post: Dear Fernando, I recently posted a thank-you message because your method of driver integration worked for me. Now, however, there is a problem. To recap: We purchased a refurbished Dell XPS 720 running Windows XP Media Center 2005. I was unable to set up a RAID1 array until I found your guide, which worked perfectly. However, after about two weeks, we now have a "RAID failure" and lost-access error message. The computer came with a Seagate Barracuda 320-GB HD. The second drive we added is an identical Seagate Barracuda. The RAID array error message from the nVidia MediaShield program says the array is "degraded." The newer of the two drives is still working and the computer is functioning normally. What do I do next? How do I figure out if this is a software problem, non-disk hardware problem, or the disk has actually failed? I tried running Seatools for DOS on the hard drive and got an error message but I have a feeling that Seatools does not run correctly on a mirrored drive. ADDENDUM: After a few days, NVIDIA MediaShield's message has changed. Both drives now read as "Healthy" but the RAID array is "Degraded." No popup or context (right-click) command is associated with HD0, but "Delete Array" appears when I click on HD1. No "Rebuild Array" command is available. I've tried going into the RAID manager at machine startup prior to OS loading, but the Rebuild Array command does not seem to work, i.e., nothing happens when I try to execute it.