Create a Bootable USB to Install Windows

Creating a bootable USB to install Windows is the first step of any clean installation or reinstall — whether you’re setting up Windows 11 on a new PC or repairing an existing one. In this guide, you’ll create a bootable USB drive with Rufus in about ten minutes, from downloading the ISO to plugging it in and booting.

What you’ll need

• A Windows ISO file. If you bought your license from Flixeasy, the official ISO download link is included in your delivery email. You can also download it directly from Microsoft’s Download Windows 11 page (or the Windows 10 equivalent).
• A USB flash drive of 8 GB or more. Everything on it will be erased, so back up anything you want to keep.
• Rufus. A free, tiny tool for writing ISOs to USB — download it from the official Rufus website. No installation needed; it runs directly.
• A valid product key. You’ll enter it during installation. If you don’t have one yet, you can get a genuine Windows 11 product key or Windows 10 product key with instant email delivery.

Creating the bootable USB with Rufus

Step 1 — Plug in your USB drive and open Rufus

Insert the USB stick and launch Rufus. No setup wizard — it opens straight to the main window.

Step 2 — Select your USB drive

Rufus detects connected drives automatically. Under Device, confirm the right USB drive is selected — double-check the size so you don’t wipe the wrong drive.

Step 3 — Select the Windows ISO

Make sure Boot selection is set to Disk or ISO image, click SELECT, and browse to the Windows ISO file you downloaded.

Step 4 — Keep the default image options

Choose Standard Windows installation. Rufus picks the correct Partition scheme (GPT for modern UEFI systems) and Target system automatically — leave them as they are unless you know your PC needs legacy BIOS/MBR.

Step 5 — Name the drive and start

Give the Volume label any name you like (e.g. “WIN11”), leave File system and Cluster size at their defaults, and click START.

Step 6 — Confirm the warning

Rufus warns that all data on the USB will be destroyed — that’s expected. Click OK and the write begins. It typically takes 5–15 minutes depending on your USB speed.

Step 7 — Done

When the status bar shows READY, close Rufus. Your bootable Windows USB is ready to use.

Booting from the USB and installing Windows

1. Plug the USB into the PC where you want to install Windows.
2. Power it on and press the boot-menu key repeatedly — usually F12, F11, Esc or F9 depending on the manufacturer.
3. Select the USB drive from the boot menu.
4. Follow the Windows Setup wizard: choose language, click Install now, and enter your product key when asked.
5. Pick Custom install for a clean installation, select the target drive, and let Setup finish — the PC restarts several times.

After installation, Windows activates automatically once you’re online. If you need a license, every Windows product key from Flixeasy is delivered by email within seconds, with lifetime activation and no subscription.

Frequently asked questions

Can I use the same USB for Windows 10 and Windows 11?

One USB holds one ISO at a time. Repeat the Rufus steps with a different ISO to switch — or use a tool like Ventoy if you regularly need multiple installers on one drive.

Rufus says my ISO is invalid — what now?

The download is probably incomplete or corrupted. Re-download the ISO from Microsoft and try again; Rufus verifies the image before writing.

Do I need to format the USB first?

No — Rufus formats the drive as part of the process. Just make sure nothing important is stored on it.

My PC won’t boot from the USB

Enter the BIOS/UEFI settings (usually Del or F2 at startup), make sure USB boot is enabled and Secure Boot allows it, and move USB above the hard drive in the boot order.