How to Install Windows 11 on Legacy BIOS without Secure Boot or TPM 2.0

Want to Install Windows 11 on a Legacy BIOS without Secure Boot and TPM? Well, here’s a workaround that works 100%.

The excitement level of installing a new Windows operating system remains just the same and most of us have had the pleasure to experience it multiple times. However, the excitement is flushed down the drain when you encounter an error for a problem that just cannot be dismissed out of hand.

One such issue with installing Windows 11 is, it requires ‘Secure Boot’ along with ‘TPM 2.0’ enabled on a machine, and it is a pretty straightforward process to enable both of these options if you are on a ‘UEFI’ BIOS Mode. However, on a ‘Legacy BIOS Mode’, it’s a different ball game altogether.

Since switching to ‘UEFI’ from ‘Legacy’ BIOS Mode could completely wipe the disk, some might not be very comfortable with the trade. And even switching to UEFI does not guarantee the installation of Windows 11, as many older computers do not have the option to enable TPM 2.0 in BIOS. However, it’s debatable as of yet if TPM 2.0 is really required for Windows 11.

READ → How to Fix ‘This PC can’t run Windows 11’ Error

Thanks to the massive community of Windows users, there are already workarounds to bypass the Windows 11 Secure Boot and TPM 2.0 requirements with a harmless Registry hack or by modifying the Windows 11 ISO files.

Let’s explore both methods one by one below.


1. Modify Windows 11 ISO Files to Boot Install from Legacy BIOS

The first workaround for installing Windows 11 on a ‘Legacy BIOS’ without Secure Boot and TPM is really effortless, provided you have all the pre-requisites mentioned below.

Pre-requisites:

  • Windows 11 ISO Image
  • Bootable Windows 10 USB Drive (→ instructions)
  • A computer running Windows 10 (preferably)
  • 8GB USB Flash Drive

What’s the workaround? Basically, you need to create a bootable Windows 10 USB drive and then replace the install.wim or .esd file in the ‘sources’ folder in Windows 10 USB with the install.wim .esd file from Windows 11 ISO image.

First, mount the Windows 11 ISO file by right-clicking on it and selecting the ‘Mount’ option from the context menu.

Then, open the mounted Windows 11 ISO image and navigate to the ‘sources’ folder inside it.

Then, locate the install.wim file in the ‘sources’ folder of Windows 11 ISO image and copy the file using the Ctrl + C shortcut. Alternatively, you can also right-click the file, and select the ‘Copy’ option from the context menu.

Now, plug in the bootable Windows 10 USB drive to your computer, and open it in File Explorer. Then, open to the ‘sources’ folder inside the Windows 10 USB drive.

Finally, paste the install.wim file you copied from Windows 11 ISO image in the bootable Windows 10 ISO USB drive ‘sources’ folder using the Ctrl + V shortcut. You can also right-click on any empty space in the folder, and select the ‘Paste’ option from the available options.

Since the file will be present in the Windows 10 USB drive ‘sources’ folder as well, you’ll get a Replace or Skip Files dialog. Make sure you choose the ‘Replace the file in the destination’ option from the dialog box.

Once the file has been copied to the bootable Windows 10 USB drive, reboot your computer. And then from the ‘Boot device options’ on your Motherboard, boot your system with the bootable Windows 10 USB drive.

Note: Do not worry about booting the Windows 10 USB drive. The installer you’re running is of Windows 11 as we copied the install.wim file from the Windows 11 ISO image to the Windows 10 USB drive.

Once your USB drive has booted, you’ll see the option to select and install a Windows 11 version. It’ll also pass the security checks without enabling ‘Secure Boot’ or ‘UEFI’ in BIOS.

2. Registry Hack to Bypass Secure Boot and TPM 2.0 Check in Windows 11 Setup

You can bypass Secure Boot and TPM 2.0 checks during Windows 11 installation by modifying some registry key values on your Windows PC. It’s a pretty simple and harmless hack that you can easily apply to any PC.

To get started, first, press the Windows + R keys together on your keyboard to launch the Run box on your computer. Then, type regedit and hit enter to launch the Registry Editor on your PC.

In the Registry Editor window, navigate to the following directory:

Computer\HKEY_LOCAL_MACHINE\SYSTEM\Setup 

Then, right-click on any empty area on the right panel, select ‘New’ followed by the ‘Key’ option.

A new Registry key will be added to the left side in the Registry Editor. Be sure to name the new key LabConfig.

Now, under the ‘LabConfig’ key, create a new DWORD value by right-clicking on the empty space selecting ‘New’ followed by ‘DWORD (32-bit) Value’ option.

Give this value the name BypassTPMCheck. And after that, similarly, create another DWORD value with the name BypassSecureBootCheck.

Then, double-click on the BypassTPMCheck key to open the edit box, and input 1 value in the ‘Value data’ field and then click on the OK button.

Similarly, edit the BypassSecureBootCheck value and input 1 in the Value data field and hit the OK button.

Once done, close the Registry Editor window and restart your computer for the new Registry key to take effect.

Then, try running the Windows 11 setup by mounting the Windows 11 Preview ISO on your Windows PC. It shall bypass the TPM 2.0 and Secure Boot checks and let you install Windows 11 on any old PC.


Workarounds That Don’t Work For Legacy BIOS

Since they are a lot of people trying to install Windows 11 to a ‘Legacy BIOS’ system, there are a lot of workarounds floating on the Internet which are a hit and miss. Thus, we have compiled a list of common things that do not work for installing Windows 11 on a ‘Legacy BIOS’ system.

  • Copying the ‘sources’ folder from Windows 10 ISO image file and pasting it to Windows 11 ISO image file.
  • Copying the appraiserres.dll file from the ‘sources’ folder of Windows 10 ISO image file and paste it to the ‘sources’ folder of Windows 11 ISO image file.
  • For some users, the solution provided in the guide might work for a clean installation and you may not get the upgrade option which lets you keep all your files and folders. This will result in wiping off the data on the Windows drive.

Well people, you can now go and brag to your friends what a child’s play it is to resolve the errors faced during Windows 11 installation on a ‘Legacy’ BIOS system.