How to fix the operating system loader has no signature

Theo Lucia

Dec 16, 2024 • Filed to: Windows Computer Solutions • Proven solutions

While booting up your system is it displaying "operating system loader has no available signature." Any unrecognized or corrupted boot image file could be the possible reason for this. Do not worry! You can effortlessly fix it, with the solutions in this post. Apart from solving the problem, you will also know the possible causes for it. Also, learn here how to retrieve your data if it gets accidentally deleted while solving the error.

Part 1: What causes this issue?

There may be several reasons for the "operating system loader has no available signature" this message. Some of the possible ones are:

1. Corrupted Boot Image

There is a "Secure Boot" feature in the booting mode. It is in authority to check the authenticity of the boot image. If it is unauthentic or bad, you get the message – the "operating system loader has no signature."

2. Windows in BIOS

Instead of BIOS, UEFI mode is required for booting the system. If you have installed Windows in the BIOS and are trying to boot your operating system when the Security Boot is on, it won't boot.

Part 2: Ways to Fix this Error

Now you know the possible causes of getting this message - operating system loader has no available signature. Let us move to the solutions that will help you in getting rid of this error message.

Do you find the error is because you have installed the operating system in the BIOS, and the system boots from UEFI mode? If this is the case, then reset the BIOS or disables UEFI. But for any other scenarios, you need to follow the below-discussed solutions.

Method 1: Perform a Hard Reset of your computer

Hard Reset your system with the below steps to eliminate the error message.

Step 1: Turn off the system, remove all the external devices or peripherals, and power cable.

Step 2: Press the power button of the system for approx. 15 to 20 seconds.

Your system is hard reset; check if the issue is resolved. If you are using a laptop, remove the battery too.

Method 2: Try to Reset the BIOS

The second method to fix this error is by resetting the BIOS settings. Usually, every manufacturer has a different BIOS settings interface, but specific steps can help you resolve the issue. Here are the steps:

Step 1: Turn off your system and restart it. Enter the BIOS setting by tapping the right key. It can be F1, F2, Del, or F10. You can see the key displayed on the screen when you the computer restarts. Press the right key several times to enter BIOS settings successfully.

Step 2: Click on "defaults or restore" in the BIOS settings.

Step 3: Then, scroll down to the bottom of the screen, and you will see a BIOS Defaults or Restore Settings option. Click on that option and press the F9 key to load configuration. When prompted, click on Yes, it will reset your BIOS settings.

Step 4: Restart your system

Method 3: Try to Modify the Boot Sequence

You can also try changing the Boot Sequence. It can also help solve the message – the "operating system loader has no available signature." Proceed with the steps discussed here:

Step 1: Go to Windows Setting -> Update and Security -> Recovery -> Advanced Startup.

Step 2: Select Troubleshoot - > Advanced Options - > UEFI Firmware Settings

Step 3: Now, your system will restart, and you will reach Firmware settings. Here go to Boot -> Boot Priority. You can see here the list of all the connected devices. Use arrow keys to change its sequence. Once you complete it, save and exit from the setup.

Your boot sequence is changed successfully, now boot your system and see whether the error is resolved or is it still showing up.

Method 4: Try doing a Cold Boot

Cold boot is usually the primary way of resolving any issue.

Step 1: Press your system's power button and hold it until the system turns off.

Step 2: Restart your system as you usually do.

See if the issue is resolved.

Method 5: Reset your Windows 10 operating system

After trying all the methods discussed above, if the issue persists, then you are left with only one option – reset your operating system. Once you reset your PC, it will go back to the default settings, and the message – "operating system loader has no available signature" will not display.

But reset will delete all your saved data, so it is better to proceed through the Windows Recovery Environment with the following steps. It will protect your important data.

Step 1: Shut your system forcefully twice by pressing and holding the power button till it shuts down. When the system shuts down, restart it again to repeat the same step. When you turn on the system third time, you can access WinRE.

Step 2: Go to Troubleshoot -> Reset this PC -> Select the option - Keep my files/Remove everything. Once you select this option, your system will begin the resetting process. It may take some time to complete the entire process. So, do not interrupt the procedure in-between. Once it completes, you can see that the error message does not come up now.

Now browse your system and its data without experiencing any error messages.

Part 3: How to recover data from the unbootable system if the above methods fail?

A Windows operating system might become unbootable because of several reasons. A hardware issue, malware attack, corrupt registry, BIOS settings, overheating of the motherboard, etc. could be some of these causes.

We have discussed several solutions to fix the problem. However, even after trying all the solutions if the issue is not resolved, you should recover your data with the Recoverit Data Recovery software. No matter the cause of system malfunction, you can quickly recover data from your unbootable Windows 10 with the below steps:

Step 1: Select the Mode

Download and install Recoverit on some other system. Get a blank CD/DVD and connect it to the system. Launch Recoverit and select the mode – Recover from Crash Computer.

Step 2: Create the Bootable Drive

Select the connected bootable drive and click on the "create" option to start the operation.

When prompted, click on the "Format now" option to confirm the operation. It will delete all the data if any is there previously on the drive. So make sure you are not having any important files on the connected device.

Once the connected drive is formatted, it will begin with the creation of the bootable drive. Make sure the process is not interrupted, and the drive is not ejected until the process completes.

Step 3: Boot your System from the Created Bootable Drive

Once the bootable drive is created, you are now ready to boot your system and recover data in the mentioned three easy steps.

But first, make sure that you change the boot sequence of your system. For that, you need to restart your PC and change the boot sequence after entering the BIOS setting. Check out how to set the computer to boot from a USB drive.

Remember to press the appropriate key displayed on your system, to enter the Boot settings.

Conclusion

The "operating system loader has no signature" error can be bothersome, but thankfully, several solutions can help you fix this particular issue. In this article, we have discussed different methods that can easily fix this error. Try them; still, if you are unable to do so, recover data from the system with the bootable drive created with Recoverit data recovery software.