Installing Windows 11 can be an exciting experience, but it can quickly turn frustrating when you encounter errors that seem insurmountable. One common issue is the requirement for 'Secure Boot' and 'TPM 2.0' to be enabled on your machine. While this is straightforward on UEFI BIOS systems, it presents a significant challenge for those with Legacy BIOS.

Windows 11 Installation Error

Switching from Legacy to UEFI BIOS mode isn't always a viable option, as it can result in data loss. Moreover, even after switching, many older computers lack the option to enable TPM 2.0 in BIOS.

Fortunately, the Windows user community has developed workarounds to bypass these requirements. We'll explore three methods to install Windows 11 on Legacy BIOS systems without Secure Boot or TPM 2.0.

Method 1: Create a bootable Windows 11 USB drive without TPM and Secure Boot checks

This method utilizes Rufus, a third-party ISO burner software, to create a bootable Windows 11 USB drive that bypasses TPM and Secure Boot checks.

Requirements:

  • Windows 11 ISO image
  • 8GB USB flash drive
  • Rufus software (beta version)
  1. Download the latest beta version of Rufus from rufus.ie/downloads.

  2. Run the Rufus executable file.

Rufus Interface

  1. Insert your USB drive into your computer.

  2. In Rufus, select your USB drive from the 'Device' dropdown menu.

  3. Click the 'SELECT' button next to 'Boot selection' and choose your Windows 11 ISO file.

Select ISO in Rufus

  1. Under 'Image option', select 'Extended Windows 11 Installation'.

Extended Windows 11 Installation Option

  1. For 'Partition scheme', choose 'MBR' for Legacy BIOS or 'GPT' for UEFI BIOS.

Partition Scheme Selection

  1. Configure other options as needed or leave them at default settings.

  2. Click 'START' to begin creating the bootable USB drive.

Start Creating Bootable USB

Once complete, you'll have a bootable Windows 11 USB drive that can install the OS on unsupported PCs.

Method 2: Manually modify Windows 11 ISO files

This method involves replacing a key file in a Windows 10 bootable USB with its Windows 11 counterpart.

Requirements:

  • Windows 11 ISO image
  • Bootable Windows 10 USB drive
  • 8GB USB flash drive
  • A computer running Windows 10 (preferably)
  1. Mount the Windows 11 ISO file by right-clicking it and selecting 'Mount'.

Mount ISO File

  1. Navigate to the 'sources' folder in the mounted ISO.

Navigate to Sources Folder

  1. Copy the 'install.wim' file from this folder.

Copy install.wim File

  1. Insert your bootable Windows 10 USB drive and open it in File Explorer.

  2. Navigate to the 'sources' folder on the Windows 10 USB drive.

Windows 10 USB Sources Folder

  1. Paste the 'install.wim' file you copied from the Windows 11 ISO into this folder.

Paste install.wim File

  1. When prompted, choose to replace the existing file.

Replace Existing File

  1. Reboot your computer and boot from the modified Windows 10 USB drive.

You should now be able to install Windows 11 without Secure Boot or TPM checks.

Method 3: Registry hack to bypass Secure Boot and TPM 2.0 check

This method involves modifying registry values to bypass the Secure Boot and TPM 2.0 checks during Windows 11 installation.

  1. Press Windows + R, type 'regedit', and press Enter to open Registry Editor.

Open Registry Editor

  1. Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\Setup

Navigate in Registry

  1. Right-click in the right panel, select 'New' > 'Key', and name it 'LabConfig'.

Create LabConfig Key

  1. In the 'LabConfig' key, create two new DWORD (32-bit) Values:
    • Name: BypassTPMCheck
    • Name: BypassSecureBootCheck

Create DWORD Values

  1. Double-click each new value and set their 'Value data' to 1.

Set Value Data

  1. Close Registry Editor and restart your computer.

  2. Run the Windows 11 setup by mounting the Windows 11 ISO on your PC.

The installation should now proceed without TPM 2.0 and Secure Boot checks.

Ineffective workarounds for Legacy BIOS

Be aware that the following methods do not work for installing Windows 11 on Legacy BIOS systems:

  • Copying the 'sources' folder from Windows 10 ISO to Windows 11 ISO.
  • Copying the 'appraiserres.dll' file from Windows 10 ISO to Windows 11 ISO.
  • Some users may only achieve a clean installation, losing the option to keep files and folders during an upgrade.

By following one of the effective methods outlined above, you should be able to successfully install Windows 11 on your Legacy BIOS system without the need for Secure Boot or TPM 2.0.