select disk 2 clean create partition primary active format fs=ntfs quick assign letter=Z exit Run with: diskpart /s make_bootable.txt (verify disk number first).
Author: Technical Research Division Date: April 14, 2026 Version: 1.0 Abstract Installing Windows 10 from an external hard drive (HDD or SSD) is a practical alternative to using a USB flash drive, especially when larger storage capacity or specific hardware limitations are factors. This paper provides a detailed, step-by-step methodology for creating a bootable external hard drive containing Windows 10 installation media, configuring system BIOS/UEFI settings, performing a clean installation, and troubleshooting common errors. It also compares the external HDD method with traditional USB flash drive installations. 1. Introduction While Microsoft officially recommends using an 8 GB or larger USB flash drive to install Windows 10, external hard drives—often more readily available in larger capacities—can serve the same purpose. However, because external drives are typically formatted differently and may contain multiple partitions, the preparation process differs from that of a standard flash drive.
diskpart list disk select disk 2 (example) clean convert mbr (or convert gpt for UEFI) create partition primary size=8000 (minimum) active format fs=ntfs quick assign letter=W exit Then extract ISO contents using 7-Zip or mount the ISO and copy all files to W:\ . Finally, run:
Save as make_bootable.txt :
