All data on the external hard drive will be destroyed during this process.
While external HDDs are slower than flash drives and require more preparation, they are a reliable alternative when no USB flash drive is available or when larger installation files (e.g., multiple OS versions) are needed.
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 install windows 10 from external hard drive
You need the raw Windows installation file.
| Factor | Flash Drive (USB 3.0) | External HDD (5400 RPM) | |--------|------------------------|--------------------------| | | ~5–10 min | ~15–30 min | | Installation speed | Fast | Moderate (slower read) | | Reusability | High (can be repurposed) | Lower (takes full drive) | | Portability | Excellent | Bulky | All data on the external hard drive will
Use an external SSD if possible for near-flash-drive speeds with larger capacity.
Downloaded from the official Microsoft website. Method 1: Using an External Drive as Installation Media | Factor | Flash Drive (USB 3
This is the step most people miss. Simply copying the files isn't always enough; the drive needs a "boot sector" written to it.
Run with: diskpart /s make_bootable.txt (verify disk number first).