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Missing Operating System or Operating System Not Found

Missing Operating System or Operating System Not Found

Troubleshooting This Common Windows XP Error

After switching on your computer or after restarting Windows XP you receive the error message ‘Missing Operating System‘ or ‘Operating System Not Found‘.

The above error messages are usually caused by the following:

  • Incorrect Setup Utility settings (BIOS)
  • Loose or disconnected IDE cables (the cable that connects the hard disk to the system board)
  • Damaged Hard Disk
  • Incorrect or No Partition set as Active.

It can be tricky to diagnose and ideally you want to be doing as little digging inside the case as possible.

I’ll try to rule out software causing the problem first, by checking BIOS settings and then upgrading the BIOS if possible.


Step 1 – Check BIOS (or Setup Utility as it’s sometimes called)

  1. Accessing the BIOS
    • When you first switch on your computer you should see either a colorful screen with a logo or a black screen with white writing
    • There should be a message indicating what keys to press to enter the Setup Utility or BIOS.
    • Often the key is either DEL, F2 or F12 but all manufacturers vary.
    • Here’s a really good site that has most manufacturers
  2. When you enter the BIOS/Setup Utility you will need to locate the section that lists all detected hard disks in your computer
    • As an example, I’m going to use an Award BIOS (as shown below).
    • When you enter the BIOS you will see something like this:
  3. Select Standard CMOS Features and hit ENTER. You will see something similar to the following:
  4. Now that you’ve got this far, here are your options –
  • Option A) You see [Not Detected] for all options from ‘Primary IDE Master’ down as far as ‘Serial-ATA 4 Channel’
  • Option B) You see one device detected
  • Option C) You see more than one device detected

Option A – Check the Hard Disk Cables and Jumpers

  1. Power down your computer and unplug it from the socket. Safety first!
  2. Open you’re computer by following the manufacturers instructions (be careful of static electricity. Ground yourself and wear a static bracelet preferably)
  3. Locate the rear of the hard disk which will have a wide (about 2 inches) usually grey flat cable coming out of it. Make sure this cable is snuggly fitted into the back of the hard disk. Also check the power cable while you’re there
  4. Now follow the grey cable to the system board. It should plug into the IDE0 connector and should also be firmly connected
  5. Now inspect the jumpers. Ensure that the jumper is set to ‘Cable Select’ and that no other devices are on the same grey cable
  6. Close up your case and start the computer up. Now check your BIOS again following steps 1 to 3 above.

Option B) – Is it your CD/DVD or a Hard Drive?

  • Examine the name of the device that is detected
  • Could it be your CD or DVD drive?
  • If it is it will usually have the likes of RW or DVD or CD in the text. A good way to find out is by searching Google for the exact text that you see in the BIOS.

If you have discovered that it is in fact your CD/DVD drive then your hard disk is not being detected.

If the one device is a CD/DVD drive and zero hard disks are being detected in your BIOS – Follow instructions for Option a) above to re-seat cables & check jumpers.

If the one device is a hard disk then proceed to Solution 2 below.

Option C) – Do you have 2 CD/DVD drives?

  • Examine the names of the devices that are detected
  • Do you have two CD or DVD drives?
  • Do you have two hard disks and is it detecting the hard disk that doesn’t have Windows on it?
  • Follow the instruction above in option b) to find out if you are detecting two CD/DVD drives.

    If the all detected devices are CD/DVD drives and zero hard disks are being detected in your BIOS – Follow instructions for Option a) above to re-seat cables & check jumpers. If at least one device is a hard disk then proceed to Step 2 below

Step 2 – Check the Boot Order in the BIOS

Now that you’ve established that have a hard disk detected in the BIOS we need to check the Boot sequence or boot order.

  1. Find the menu in your BIOS that controls the boot order – mine is called Boot Sequence
  2. Ensure that your hard disk is set as the first boot device (you can change this after to make your CD the first boot device if you need to)
  3. If you’re boot order is set correctly and you are still seeing the error message then proceed to Solution 3 below

Step 3 – Set Partition Active

Now that the BIOS is sorted hopefully, if you are still receiving the error you must ensure that the correct partition is set as active.

  1. Boot your computer using your Windows XP setup CD and select the Recovery Console option on the Welcome screen
  2. If requested, choose your Windows installation and enter your administrator password
  3. At the command prompt issue the following command and press ENTER:

  5. At the diskpart command prompt issue the following commands and press ENTER after each:

    SELECT DISK {disk}

    Note: Replace {disk} with the disk number that your Windows installation is on as displayed following the LIST DISK command

  7. At the diskpart command prompt issue the following commands and press ENTER after each:

    SELECT PARTITION {partition}

    Replace {disk} with the disk number that your Windows installation is on as displayed following the LIST DISK command.

  9. At the diskpart command prompt issue the following commands and press ENTER after each:
  10. ACTIVE


  11. Remove your Windows XP CD and restart your computer
  12. If you have tried all the above and your hard disk is detected OK and set as the first boot device and you’re still getting the “Missing Operating System” or “Operating System Not Found” message then I would recommend reading through some of the other solutions listed in my Windows Startup Troubleshooting Guide as performing some of the actions in them have proven to fix this issue too.


Wow, 8 Comments! We've got a conversation going now. Join the discussion below!

  1. Joshy says:

    In my own case it was the BIOS battery. I changed it and message disapeared.

  2. Amit says:

    Hi ,
    Same message as ‘Missing operating system’ is displyed on my friends HP Compaq CQ40 Laptop with XP as OS .
    I tried to find Hard drive in BIOS ,bt not success.after presing ESC and then F10 i can get into BIOS. I also checked ‘Hard drive Test’ all are completed and successful.
    Can you help me to enable partition ?
    Thnx in advanced!!


  3. Rosco says:

    Hi Amit,
    On this system you set the boot order by entering the BIOS, going to System Configuration > Boot Order. See manual here: https://h10032.www1.hp.com/ctg/Manual/c01662442.pdf

    If the harddrive is not detected in the BIOS at all then it’s likely a loose cable or the hard disk could be fried.

    Hope this helps.


  4. jon says:

    I Have trouble with installing a brand new Laptop. I would like to install the OS but when I finish partitioning my laptop………….an error appeared
    All has been detected in the BIOS but why it cannot install..
    I try to install the WINDOWS XP OS in my LAptop.
    It will setup but It will stop an error has been detected….
    The error said I need to see the newly installed HDD or remove it….

    Please help me with my problem……..

    Thank You!!!

  5. suits says:

    thanks. this is all i’ve been searching for. i’ve been having problem with my computer lately and i have to use my friends computer just to surf the net.

  6. Anonymous says:

    SDned Dec 1, 2010 5:47am GMT
    I tried to clone my 200GB to a 1TB using Acronis True Image 2009. I tried this several times w/ three different hard drives,all new.

    Each time got “missing operating system ” when I booted up the new drive. All the data ,ie text,songs & photo did transfer but for some reason apparently the MBR or boot sector could not be found.

    I tried using Recovery Console to fix mbr & fixboot. Tried reformating the HD. No luck.

    Finally found the fix. I had been setting up the TI program to transfer the info from source to target drive “proportionately” each time. When I set the transfer to be done “as is” the cloned drive was bootable. Finally success!

    Now the only downside was that only 200 GB was usable on the TB drive. The rest,close to 800 GB was unallocated. But not to worry because the fix was easy.

    So I had to resize the partition. Using Easeus from Download .com , I was eassily able to move the partition to the right so the formally unallocated space was added to the newly named C drive volume such that all the drive space was now fully usable.

    Maybe this will help somebody so they don’t have to go through what I did.

  7. Unplug any USB external drives including thumb drives and reboot

    If no USB drives are attached,
    Check if disk shows up in BIOS.

    If it doesn’t, replace disk. If the replacement disk is detected, load OS on the new disk.
    If the new drive is not detected either, troubleshoot for bad data bus or use alternate databus (IDE if SATA or vice versa) or replace PC.

    If disk is detected in BIOS,
    Check whether RAID settings in BIOS are expecting additional disks.
    Set it to match current configuration.
    (Installation of SQL has caused this in two instances)

    If the RAID configuration isn’t the issue,
    Replace CMOS battery on motherboard.

    If CMOS battery replacement doesn’t help (or you don’t have a battery to work with),
    The bus or drive controller may not be working properly.

    Connect an IDE drive and try to load Windows on THAT.
    (If already using IDE drives and a SATA data bus is available, do that instead)

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