How can I upgrade or install Windows 11 on surface book 1st gen?

Installing Windows 11 on Surface Book for free is possible, provided your device meets the minimum system requirements. Here's a step-by-step guide to help you through the process:

1. Choose Download Windows 11 Disk Image (ISO).
    Select Windows 11 and click Download.
    Pick your language and edition if prompted.

2. Use Microsoft's Media Creation Tool.
    Insert a USB drive (at least 8 GB).
    Follow the tool instructions to create a bootable Windows 11 installer.

3.  Restart your Surface Book and enter BIOS/UEFI settings:
    Usually by pressing Volume Up + Power button during startup.
    Navigate to Security or Boot menu.
   Enable Secure Boot.
   Ensure TPM 2.0 is enabled.
   Save changes and exit.

4. Install Windows 11 on Surface Book
   Connect the bootable USB to your Surface Book.
   Restart and boot from USB (you might need to select boot device via BIOS or a boot menu).
   Follow the on-screen instructions:
  Choose Custom Install for a clean install.
  Select the primary partition for Windows installation.
  Proceed with the installation prompts.

5. Windows 11 can activate automatically if your device has a genuine Windows 10 license.
   If not, you may need to enter a valid Windows 10/11 product key or purchase one.

6. After installation, update drivers via Windows Update.
  Check device functionality and install any additional drivers from Microsoft or Surface support.