"Error Loading Operating System"

Ah, yes a classic problem,
one goes to boot up his computer and upon trying to load windows, is confronted with a message : "Error Loading Operating System"

I was fairly consternated when this happened to me.

Having this problem for some time I have been able to do a bit of research on the topic.
This problem most often will occur when one is trying to install a new OS, the message will appear during the reboot portion of setup.
I, however, had been running this system two years with no prior problems.
When this was the case, for other people, the HD was often corrupted, damaged, old. After running several scans on my HD, I ruled out this possibility after failing to find the slightest error.
Going on the possibility that the Windows installation may be corrupted (Note: I can boot Windows off a floppy disk, made to boot Windows XP) i tried the FixBoot and FixMBR functions on my install disk. No luck.
I installed a working version of BartPE on my HD, and I got the same result when I tried to load that instead of Windows, this makes me think that the problem is not with the Windows installation.
Just to be on the safe side though, i did a repair installation of Windows, no luck, upon restart I was confronted with the same message.

Well, I figured, the problem must be with the BIOS. So I flashed it (the equivalent, in this case, of replacing the current BIOS with an updated version). Well, the new version came with a nice menu for booting options, but it didn't solve my problem, I still received the same error message.

I was out of ideas until a ran across a solution. In other cases I found, the BIOS would be reading the HD with the wrong geometry. So if the HD on the BIOS was set to CHC, and the HD should be read as LBA, it would not work. I thought this must be it. I went into BIOS setup and discovered that there were two options: AUTO and LARGE. Currently it was set to AUTO. So I changed to LARGE. And.......
it didn't work. I changed it back to AUTO, to no avail. So I removed the HD from the BIOS setup (changed IDE1 to "none")
unable to get BIOS to register the HD again, I flashed the BIOS, again with the same version.
It was able to recognize the HD drive like before, but still could not read off of it. I am now out of ideas, and so I am posting my problem here.


I do not think the problem is with the installation of Windows, since BartPE will also not start. I could try reinstalling windows, but since this problem typically occurs during the restart portion of setup, and the repair install did not work, I do not think that reinstalling windows is the answer.

I can boot off of a floppy disk that is made to boot up Windows. I did try replacing the OS files on the HD with the corresponding ones on the floppy disk, did not work.

To be clear:

1. I turn on the computer
2. BIOS comes up with it's list of options (i.e press DEL for Setup, press F9 for Boot options.. etc...)
3. The screen changes to display the system stats (IE. temp, fan RPM, etc...)
4. Below, it starts to boot of HD, "Verifying DMI Pool Data..."
5. It displays an error message "Error Loading Operating System"


I am running on a Biostar GeForce 6100 M-9 Motherboard
using a SATA2/RAID 250GB HD.
With a Windows XP Home Edition SP2 Installation.
BIOS Id: C51MCP51-6A61HB09C-00


I was not sure where to post this, sorry if I mis-posted in wrong section

I had that error after removing Windows 7 and trying to re-install XP Pro. I also tried the FixBoot and FixMBR functions on my disk with no luck. I deleted all the partitions and started over also with no luck. In the end I downloaded the Western Digital Tools for my drive and wrote all 0's to the drive. After that I was able to install XP again.

@Joshua

Just trying to clear up what I understood from your post:
- your PC will not boot directly from the hard drive
- your PC is perfectly able to boot from anything but the HDD and will be happy to use (aka. read and write) the information stored on the HDD
- the MBR and BIOS settings have been debugged into oblivion as far as you can tell and it's not an OS related issue

So far so good and it'd seem that your approach is rather exhaustive and well though out. In my opinion, the most likely causes for your issue are:
- an HDD that has issues and is about to fail
- a faulty or improperly connected SATA cable
- a faulty SATA controller on the motherboard

You should be able to check the cable rather easily (simply grab a new one from a store, they are rather cheap and having a spare will definitely not do any harm).

I'm also assuming (or rather hoping) that there is more than one SATA controller on your motherboard in which case you should be able to simply plug the HDD in a different one and see what comes of it.

Another simple step that I'm not sure you've already taken is to download and burn a CD containing the diagnostic tools provided by your HDD's manufacturer and run their diagnostics. From the description you made it's not clear if you checked the drive using anything beyond the tools that tend to come with an OS (Windows' chkdsk or similar) or partition manager. I'm not entirely sure that all HDD manufacturers provide such tools but in case you have a Seagate drive here's a link to theirs: http://www.seagate.com/www/en-us/support/downloads/seatools. The DOS (aka. bootable CD image) is the version you want. You'll need to provide a valid e-mail address before they let you download, I think.

If all this fails to come up with a reason for you issue zeroing out the HDD and trying to reinstall is a valid option that might work if the drive is only slightly ailing. However, I'd suggest checking out if the warranty has expired and having it sent back to the manufacturer for a diagnostic if it's still covered.