My understanding is that the Dimension E310 machine I am working on does not require any "F6 Drivers".  All the code required is firmware in the Intel Option ROM chipset and the Phoenix system BIOS.  It that not correct?   The OS is the original factory-installed XP Media Center Edition 2005.

Dell Dimension E310 DV051 Series

Phoenix ROM BIOS PLUS Version 1.10 A04 04/04/06

Intel Matrix Storage Manager option ROM v5.0.2.1005 ICH6R

SATA-0 WDC WD800JD-75MS

SATA-2 WDC WD800JD-75MS

Pentium 4:  2.80GHz CPU; 800MHz Bus; 1MB L2 Cache; Hyperthreading Capable Yes; EM64T 64-bit;

Memory: 2x512MB DIMM DDR2 SDRAM 533MHz; Dual Interleaved; ECC no; Unbuffered;

Windows XP Media Center Edition 2005

ether333;

You have cleared up something for me that I've been wondering about.  If your RAID was still active, changing the SATA controller to Autodetect should have still allowed the machine to boot.  That is what RAID Autodetect/ATA is all about; if you have no RAID, the controller gets set to a Parallel ATA/IDE compatible state that allows the old IDE drivers to work with your SATA drives.  Windows XP was produced a long time before SATA became widespread in PCs, so most copies of the Windows XP installation disk only have the drivers for IDE.  That is what Speedstep is writing about.  Unless you have one of the Win XP install disks that Dell released for SATA machines (they had the SATA drivers slipstreamed into them), or a copy of Windows XP with Service Pack 3 already included on the disk, Windows XP Setup can't see a SATA controller that has been AHCI enabled, which includes the RAID On setting.

Since your RAID has already been disabled, the only feature that the RAID setting enables for you is the AHCI interface.  Since your computer was set up using RAID On, that is the driver that your Windows XP installation is using.  When you switch to Autodetect, AHCI is disabled, and you need the old IDE driver, which has not been installed on your system, in order for Windows XP to see the hard drives.  Consequently, when you make the switch, you have no hard drives.

At this point, you can do pretty much whatever you wish with the second drive.  You can use the Intel Matrix Storage application to migrate back to RAID 1, you can repair it for use as a spare system drive, or you can delete all existing partitions, reformat, and simply use the second drive for data.

rdunnill;

Not necessarily.  There are complications as he is using Media Center, and we don't know if his installation disk (assuming he has one) has the SATA drivers.

He states that he has managed to repair one disk, and is using that to boot.  If I were in his place, I would save the working drive as a back-up, and try to repair the second drive for use (assumes he doesn't want to deal with RAID anymore).  Since his SATA controller is set to RAID On, and the computer is working with at least one drive, it is safe to assume that the SATA drivers are already contained in his existing installation.  I nearly always follow the philosophy of "if it ain't broke, don't fix it".  I frequently regret ignoring that maxim.

If this is the case, an XP Repair Install should make the primary drive bootable.

Clearing up some misunderstandings:

1) both hard disks are physically fine. Both passed the testing performed by the "Hard Disk Diagnostics" boot menu option.  I understand that you can't fix a physically inoperative disk by installing software on it.

2) the two hard disks are the exact same model

3) I have multiple image backups of the entire disk, and separate image backups of the individual partitions.

4) I have a backup of the MBR using Dan Goodell's MBRSAVER program

5) I do not have any Windows installation media for this machine.  That is why I do not want to destroy the ability to restore using the factory image in the DellRestore partition.  Even if I had Windows installation media, I don't want to have to hunt for all the machine-specific drivers and figure what order in which to install them.  Been there, done that on other machines, don't want a repeat experience.

6) I don't think I need to download or install any "F6 drivers".  They should already be in the factory image, since the machine was shipped from the factory with these very disks in RAID Level 1.

7) I have filesystem-level backups of the data

8) The disks are presently NOT in a RAID volume.  They show up as individual disks in the boot menu (F12), in the BIOS setup (F2), and in the Intel Option ROM screen (CTRL-I).

9) Disk0 has been restored to factory condition using CTRL-F11 to access the factory image in the DellRestore partition.  Disk1 is presently unreadable, not because of any physical reason, but because the MBR got trashed earlier and I have not yet restored it.  

10) Both disks are physically connected to their respective power and data lines, in the original factory configuration.

11) The orginal factory setting in system BIOS for RAID was "RAID Auto".

12) I get the BSOD with the "STOP 7B" code when I set the RAID to "AUTO" in the BIOS. When I set the RAID to "ON" in the BIOS, the machine boots and operates normally.  I would like to understand why this is.

OK, I get it now.

What difference is there, if any, of using "RAID drivers" for non-RAID disks compared to using "IDE compatible drivers"?

Is there a performance hit?

OK, I get it now.

What difference is there, if any, of using "RAID drivers" for non-RAID disks compared to using "IDE compatible drivers"?

Is there a performance hit?

The RAID On setting, in addition to enabling the controller to handle a RAID, uses the AHCI - Advanced Host Controller Interface.  As I believe was mentioned earlier in the thread, the best known enhancement attributed to the AHCI is command queuing, a technique designed to execute instructions in the most efficient order.  The AHCI also enables hot plugging on those computers having a BIOS designed to support it.  Using the AHCI speeds up the data transfer to and from the hard drive by a few percent, but to be honest, the increased speed is small enough that most people would not notice.  I've spoken to gamers who swear that the speed increase is enough to have a significant impact on their game play, but for someone like me who uses the computer more for data retrieval and word processing...well, I think you get the point.

In any case, as I stated earlier, the enabling of the AHCI is the only thing that is important to the RAID On setting in a computer that has no RAID.  If your computer has only a single hard drive, or multiple drives but no RAID, you can look at RAID On the same as you would look at a setting that says AHCI, or in some machines, RAID Autodetect/AHCI.

This is starting to make more sense.

This machine's BIOS does not have "RAID Autodetect/AHCI"; it only has these two options:

1) "RAID Autodetect / ATA = RAID if signed drives, otherwise ATA"

2) "RAID On  =  SATA is configured for RAID on every boot"

... so if I set it to #1 above, and it doesn't see "signed" drives, it uses ATA, and my factory installation of Windows does not have ATA disk drivers, thus the BSOD with STOP code 7B?

What is a "signed" drive?  Where on the drive is the "signature" ?

The signature is the parametric data I described earlier.  If the parametric data = signed is present, the RAID controller recognizes the drives and sets up the controller for the appropriate type of RAID.  If the drive or drives lack the "signed" part and the controller is set to RAID On, you are left with the AHCI.  Remember, you removed the signature when you deleted the array, the drives were left "unsigned".