Create Bootable USB: Windows Installation Media Made Easy

To create a bootable Windows USB installer using nothing but tools built into Windows, follow the steps below.

Requirements

A USB stick of at least 8GB (Windows installation images have grown well past the old 4GB FAT32 limit for many releases, so 8GB+ is the safer minimum today) and a Windows ISO file.

Steps

1. Open an elevated Command Prompt.
2. Type diskpart and press Enter.
3. Run list disk and identify your USB stick by its size — be certain you’ve picked the right one, as the next steps erase it completely.
4. select disk # (replace # with the correct disk number)
5. clean
6. create partition primary
7. select partition 1
8. active
9. format fs=fat32 quick (use ntfs instead if your install.wim is over 4GB and your target PC boots UEFI with CSM/legacy support that handles NTFS, though FAT32 is the safer default for broad UEFI compatibility)
10. assign
11. exit

Then mount your Windows ISO (double-click it in File Explorer) and copy every file from the mounted drive to the root of your USB stick — either drag-and-drop in File Explorer, or robocopy D: E: /E (adjusting drive letters for your ISO mount and USB stick). For a simpler one-command alternative, Microsoft’s own Media Creation Tool (for consumer Windows versions) automates all of this for you if you’d rather not do it manually.

When FAT32 Won’t Work: Windows 11 ISOs Over 4GB

Current Windows 11 ISOs (24H2 and newer) frequently ship an install.wim or install.esd file larger than the 4GB single-file limit FAT32 imposes, which breaks the classic diskpart-and-copy method above at the file-copy step. If you hit this, you have two options: split the install image into smaller .swm files with dism /Split-Image and keep the USB stick FAT32, or format the stick as NTFS instead and add a small FAT32 “UEFI:NTFS” boot stub so the firmware can still find a bootable FAT32 partition while the bulk of the files sit on NTFS. Doing this by hand is fiddly, which is why a tool like Rufus has become the practical go-to for this scenario — it automates the UEFI:NTFS workaround natively, and also offers an “Extended Windows 11 Installation” option that strips the TPM 2.0, Secure Boot, and RAM checks from Setup for installing on unsupported hardware. That bypass works, but Microsoft doesn’t guarantee update servicing on hardware that doesn’t meet the official requirements, so treat it as a supported-but-unofficial route rather than a first choice. Microsoft’s own Media Creation Tool doesn’t offer either workaround and sticks to officially supported hardware only.

Resources

• Windows

One more thing worth knowing before you commit to a drive: USB sticks larger than 32GB often refuse to boot even after they have been written correctly, because the boot partition needs to sit inside a size range the firmware expects. If that happens, repartitioning the drive with DiskPart fixes it.