That was the message I was getting on my Asus P5k-E. It was because I did not have RAID originally on the main SATA controller. Whilst you can apparently subsequently tell the BIOS to use RAID, windows does not have the driver, and cannot install that driver unless it knows about there being a RAID controller. And you can't tell it about a RAID controller while you are using it in IDE mode. So it thinks the system does not have a RAID controller, so it does not meet the minimum specification. At least, that is how I have rationalised the message.
It took me two full days to wade through all of the registry hacks on various sites including this one, and find none worked for me.
Also along the way, I had thought that I had made changes to the BIOS, but there was a brief message on the screen which said something along the lines of "not enough flash memory to enable options". Maddeningly it only has 64k to cover all settings. So changes had not "taken".
I had bought a pair of 1TB WD Caviar Black hard disks, but they were proving useless. I used the method outlined in post 92 by tooshio, but had to do it through a PCI card SATA controller as I did don't have an IDE hard disk to put on the other controller with the DVD drive.
Windows immediately recognised the PCI SATA card and installed it.
I attached my C drive to the additional controller, then disabled (in BIOS) all of the other controllers except the main IDE one. Only the C drive was now attached. I had to make sure it was recognised in BIOS as the boot disk. That gave enough BIOS flash memory to change the settings on the onboard controller to enable RAID. Several reboots ensued, and finally I had got it right and Windows recognised the RAID controller. As tooshio says, don't allow windows to install the RAID controller from its found hardware dialogue. Instead (post 92 item 8) install the Intel Matrix Storage Manager, and continue. Reboot and once Windows has recognised the RAID controller properly I then shut down, put the C drive back onto the main controller and made sure it would boot up. (Remembering to change the BIOS boot order again!) And use the correct SATA ports. Not sure of your motherboard, but on mine 1-3 and 6 are bootable SATA ports in red.
THEN, I physically removed the PCI card, and added both hard disks (on SATA 4 and 5 as I was only using them as data disks.) BUT I did not yet set up a RAID array in BIOS. I had to initialise and register (I think that was the term) the hard disks first. In Windows XP, that is done through Disk Manager which you will find by right clicking "My Computer" and choosing "Manage". One of the options is the hard disks. Use this to make sure you have the drive letters you want on each drive. I had to move one of them to S (after all the memory card drive spaces) to give me space to put my D drive where I wanted it, and then bring it back to E.
Once they were showing in explorer, it was another reboot, and this time I went in to the RAID array options, and set up the RAID 1 array with my two new hard disks. As they were empty it was very quick. On booting, Windows recognises them as one disk. I was then able to use the Clone software downloaded from WD website to copy my data to the new drive. (The software is actually Acronis, and only works if you have a WD hard disk. For anyone else reading this, Maxtor/Seagate also has their version of it for download, and I guess most others do too.)
What a clart on it was. I hope that my explanation helps and apologise for it being long winded. I see you have Windows 7 and hope that when I get my copy and install it, all will work. My issues arose because of wanting to get more space for my photos, and enough space to install Windows 7 on its own drive.