How to Fix Error “Operating System Not Found” on Sony Vaio?

This article shows you how to fix error “operating system not found” on Sony Vaio, and provides ways to fix the error for all major laptop brands such as HP, Samsung, Toshiba, etc.


By Cherry / Updated on May 12, 2023

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Error: Operating system not found on Sony Vaio

“I have an older Sony Vaio Laptop, model VGN-NR280E, that was loaded with the Vista operating system. I used it well,but recently, it shows an error when booting: operating system not found. What’s wrong with it? How can I fix it? Any help would be thanks.”

Operating System not Found

How to fix error “operating system not found” on Sony Vaio?

To fix the error “”operating system not found” on Sony Vaio, you can do as the following steps:

1. Shut down laptop by holding the power button on the keyboard.
2. Start laptop by holding the Assist button on the keyboard. The laptop will automatically go to “VAIO Care” mode of Sony Vaio.
3. Choose “Start BIOS setup”, or you can press F2.
4. Choose the tab “BOOT” on the Menu.
5. Here you need to get into “Boot Configuration”->”Boot Mode”, and you can see the current is UEFI.
6. Press “Enter” and choose “Legacy” to change the value.
7. In Extend Device Boot, change the value from “Disabled” to “Enabled”.
8. Save all that have changed by select the tab “Exit” on Menu, choose “Save Changes” -> Enter -> Yes.
9. After saved all changes, you can exit “VAIO Care” mode by choosing “Exit Setup”,Press “Enter” -> Yes.

As so far, we have repaired “operating system not found” on Sony Vaio successfully. If not, you can refer to more solutions shown in the following content.

Why “operating system not found” happened?

When you boot your Sony Vaio or other brands PC, the BIOS tries to find an operating system on a hard drive to boot from. However, if it is unable to find one, then, it will show you the error message “Operating System not found” or the error message “Missing operating system”. This error may be caused by the following reasons:

1. An error in BIOS configuration.

2. A faulty hard drive.

3. A damaged Master Boot Record.

Fix operating system not found for all major laptop brands

Here we provide you three common ways to fix operating system not found in Windows 10/8/7.

Fix 1: Change or reset the BIOS configuration

Fix 2: Check hard drive is working or not

Fix 3: Rebuild MBR

Fix 1: Change or reset the BIOS configuration

Since boot device not found or operating system is missing occurs when BIOS is unable to find the boot device, checking BIOS settings might be a good solution. To check the BIOS settings, follow these steps:

1. Restart the computer.

2. Press the key to open BIOS menu. The key depends on the computer manufacturer and computer model. It can be any of the following: Esc, Del, F2,F8, F10, or F12.

3. When you get into the BIOS’ main screen, you need to check whether it detects the hard drive, and whether the boot order is right.

4. If the hard drive is not detected properly, you should reset the BIOS settings to default values.

1>. Enter BIOS.

2>. Find the Reset to default or Setup default option - it could be a hot key, or an option in the menu.

3>. Choose the reset option, and answer “Yes” when prompted for confirmation.

4>. Then, select the “Exit -> Exit saving changes” option.

Fix 2: Check hard drive is working or not

The “operating system not found” in Sony Vaio or other brands like HP, Asus, Dell, Samsung, etc, may because of faulty hard drive. Thus, you need to check whether the hard disk is working or not in BIOS.

1. Plug the AC Adapter into the computer if it is not already connected.

2. Turn off the computer and wait 5 seconds.

3. Press the Power button to start the computer and repeatedly press the special key to enter the BIOS Setup menu.

4. Use the Arrow Keys to choose Diagnostics or Tools to check hard drive is working or not.

You can also use third-party software to check whether there are bad sectors on the hard drive. Like AOMEI Partition Assistant Standard, which allows you to do that.

1. Connect the hard drive to a valid Windows PC which installed AOMEI Partition Assistant (you can download AOMEI Partition Assistant Standard free from its official website).

Download Freeware Win 11/10/8.1/8/7/XP
Secure Download

2. Launch AOMEI Partition Assistant. Right click the hard disk you want to check. On the top pane, select TestDisk Surface Test.

System Disk Test

3. Click Start to check the hard disk.

Start Test System Disk

If there is nothing wrong with the hard drive, you can find other solutions for “operating system is not found” on Sony Vaio or other computer. If there is bad sectors, you can try to fix it or replace the disk with good one.

Fix 3: Rebuild MBR

If the “operating system not found” error is caused by a damaged master boot record, then you need to fix the MBR error.

1. Start your computer with a Windows 11/10/8/7 installation CD/DVD.

2. Click Repair Computer -> Recovery Option-> Command Prompt.

3. Type the following commands to fix MBR:

Bootrec.exe /scanos

Bootrec.exe /FixMbr

Bootrec.exe /FixBoot

Bootrec.exe /rebuidbcd

If you do not have the Windows 11/10/8/7 installation disc, you can use AOMEI Partition Assistant to create a bootable disc and rebuild MBR by AOMEI Partition Assistant.

Step 1. Use AOMEI Partition Assistant to create a bootable media (USB, CD/DVD) on another normal PC.

Step 2. Insert the bootable device you created before to the computer which displayed “Operating system not found” error, and boot the computer from the bootable media.

Step 3. It will display the main interface of AOMEI Partition Assistant after booting. Right click the disk, select Rebuild MBR.

Rebuild System Disk MBR

Step 4. Set the type of MBR for the current OS. ClickOK.

Choose MBR Type

Step 5. Confirm the operating and clickApply > Proceed.


Finally, remove the bootable device, and restart your computer from the hard drive normally.


As so far, you have learned the ways for how to solve “Operating system not found” on Sony Vaio or other brands. AOMEI Partition Assistant is more than a tool that helps you to test disk, or rebuild MBR. It is also a partition manager that can help you create partition, format partition, resize partition, etc. You can upgrade to its professional edition to unlock more functions, such as cloning GPT system disk, converting dynamic disk into basic without losing data. Well, if you are Windows Server users, you can use AOMEI Partition Assistant Server to solve those problems easily.

Cherry · Staff Editor
Cherry is an editor of AOMEI Technology, she covers backup & restore, hard disk & partitions management, cloud files transfer, website & database backup and so on for AOMEI. She enjoys helping people find solutions to their problems. She loves traveling, cooking, reading and so on. She takes most of time with her family when she is not working.