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"Operating System not found" on SCSI boot but it works if XP Setup disc is in CD drv

By bilbo
May 7, 2006
  1. I have a SCSI boot drive, running XP Professional SP1, with a large EIDE storage drive. I have been plagued with an occasional "Operating System not found" message upon trying to boot -- on and off for probably about a year. However, it only happened OCCASIONALLY until now... After a virus, I reinstalled XP Professional (it didn't destroy all data on my SCSI drive, although I had told it that it could). Now, the system will not boot at all... same "OS not found" error each time I try.

    Here's the twist: I put the XP Setup disk back in, but got distracted, and when I came back I noticed that the SCSI HDD's copy of Windows XP ACTUALLY DOES BOOT when the XP Setup CD is in as long as you do not type a key when it says "Type any key to boot from CD". Once up, the XP Setup disc can be removed and the system operates totally normally.

    So, I read through the postings I could find, and tried the closest matches (FIXMBR, FIXBOOT, copy ntldr, reinstall Windows) but nothing changes the result. My suspicion is that the bootstrap process is lacking something on my SCSI HDD's Windows install, so it flips over control to the bootldr for the CD, but then the CD yields control back to the SCSI HDD's Windows install as long as I don't type a key.... but I have yet to be able to prove this by determining what the HDD's copy of Windows is missing.

    Anyone have an idea for me to try? Am I on the right track?

  2. Nodsu

    Nodsu TS Rookie Posts: 5,837   +6

    The CD bootloader does exactly the same as the BIOS does - it just runs the bootsector of the hard drive.

    I would guess your computer just boots too fast and the SCSI monster drive doesn't have enough time to spin up when BIOS wants to boot. Having the CD in the drive gives you enough delay to have the HD up and running when needed.

    You should have some startup delay options in both the SCSI and the system BIOS. If not, then just tell your BIOS to do a thorough memory test at startup or something similar.

    You can test this by pressing the reset button after an unsuccessful boot (the hard drives will remain powered) or pausing the bootup process after the detection of the SCSI HD (press the pause key) for ~10 seconds (press any key to resume bootup)
  3. jobeard

    jobeard TS Ambassador Posts: 10,432   +801

    some scsi controllers require an option to scan lud {0-16}. make sure your
    bootable scsi drive is lud=0 and limit the scan to the default 0-1.
  4. Samstoned

    Samstoned TechSpot Paladin Posts: 1,018

    another point
    in bios make sure the scsi hardware boots first
    then the drive
    I run a U320 for boot I have the scsi utility setup manual for 320 speed
    it would not boot right if set to manual
    on my machine it's ctrl A on boot to setup
    some older machines don't like to boot from pci cards
    the bus is not up on boot order
    can try to disable most other boot options
    my cables are live Termination
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