Missing Operating System or Operating System Not Found

Description

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

Explanation

The above error messages are associated and usually caused by any of 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 so I’ll document this solution in such a way that we rule out software causing the problem first by checking BIOS settings and upgrading the BIOS if possible.

Solutions

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 be presented with a colourful screen or a black screen with white writing
   • Whatever you see, look out for an instruction of what to key or keys to press to enter the setup utility or BIOS. I have know this to be many, many keys
   • Some of the more popular ones are DEL, F2, F12
   • Here’s a really good site that has most manufacturers or you can leave a comment below and I’ll try to help you find it.
2. When you enter the BIOS/Setup you will need to locate the section that lists all detected hard disks in your computer
   • For the purposes of this article I’m going to use an Award BIOS considering that’s what I have here.
   • If you have a different BIOS and can’t find the hard disks then contact me
   • So 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] opposite 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 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. Locate the appropriate menu in your BIOS (mine it’s simply 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

   DISKPART

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

   LIST DISK SELECT DISK {disk}

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

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

   LIST PARTITION SELECT PARTITION {partition}

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

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

   ACTIVE EXIT

7. Remove your Windows XP CD and restart your computer
8. 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.