I just posted this to my company's internal knowledge base.. I thought I would pass it on to you folks in case you have this issue.
I had to google hard, high and low until my head hurt to find the answer, so I wanted to also make it easier for me to find the solution again by also submitting it to here
FYI this applies to all OS's, including WindowsXP *ducking*
"Error loading operating system" at BIOS bootup screen (WinXP, Linux, Unix)
I think I nuked the boot sector of the HD, or maybe the HD crashed... This applies to WinXP, Linux, Unix, all OS's.
Tim Smith, 10/5/04
I tried installing WinXP again, fixmbr, restore consolr, etc etc.. even installed Debian, FreeBSD, SuSE, made it all FAT32, nuked it, made NTFS, made it reiser,ext2, ext3 everything, NOTHING worked, I kept getting "error loading operating system" no matter what OS I "successfully" installed. I even used knoppix 3.6 to nuke things and repartition and format to no avail.
Don't despair there is probably good news!
The most likely solution is that your HD geometry is set wrong... On many motherboards in the BIOS setting for your HD, it is set to AUTO.. which sometimes tries to use CHS which is incorrect for most modern computers. Manually set it to LBA instead.
You may have to reformat your HD completely after manually setting the HD to LBA. I hear that you might even need to go to your HD website to download a low level formatting utility (writes 0's all across your drive). I fortunately did not have to do that.
This problem mainfested only after heavy hacking around trying Norton Ghost, Partition Magic, different Unix, Linux, Windows XP operating system, and I guess that the instability of the geometry being set wrong finally crapped out on me. Before this, it had been running only WinXP for more than 2 years with no burp!
LBA is your friend. No to AUTO, no to CHS.
Thanks to this site I found after HEAVY googling and screening out all the XP's fixmbr and fdisk /mbr suggestions that didnt help:
setting to LBA, and then ghosting from image file to the boot partition (Its a dual boot, and that happens to be winxp :P ) and I was all set to go.
HTH some of you poor saps that got yourself into the same bind I did..