Once you have the official ISO, you have two main paths: (run Windows 8.1 like a dual-boot) or virtual machine VHD (run inside VirtualBox/VMware).
Yes. The .vhd format is the older version with a limit of 2 TB for a dynamic disk. The .vhdx format is newer, supports larger capacities up to 64 TB, and has better performance and power-failure resilience. windows 81 vhd download link
But the first step is the hardest: finding a legitimate . Let's clear up the confusion immediately. Once you have the official ISO, you have
While Microsoft does not provide a direct "pre-built" VHD file for standard users, the most common way to get one is by creating it yourself from an official ISO. Official Sources While Microsoft does not provide a direct "pre-built"
Do you need this for , legacy gaming , or data recovery ? What is your host machine's operating system ?