: A 32-bit (x86) kernel cannot execute 64-bit instructions, and vice versa.

: Boot from your media, select "Custom (advanced)" installation, and format the drive. Changing from Windows 7 32 bit to 64 bit - Microsoft Learn

Use the official Windows 7 ISO download tool (if still available via Microsoft) or a trusted source. Write the ISO to a USB using Rufus (set partition scheme to MBR for older BIOS or GPT for UEFI).