To build your own VHDX, you first need the source OS files. Here are legal download options:
Microsoft provides official Windows 10 VHDX images for download, but you'll need to meet certain conditions. Here are the steps: Windows 10 Vhdx Image Download
: For those using ARM-based devices (like a Surface Pro X or M1/M2 Mac), Microsoft provides official ARM64 VHDX images for Insider Preview builds. To build your own VHDX, you first need the source OS files
: Microsoft offers pre-configured Hyper-V virtual machines that include Windows 10 and development tools like Visual Studio. To build your own VHDX
Warning: Avoid third-party websites offering "pre-activated" or "download ready" Windows 10 VHDX files. These often contain malware, rootkits, or violate Microsoft licensing terms.
You can dual-boot Windows 10 from a VHDX file without any hypervisor.