Rufus is a small, free tool that turns a Windows 10 ISO file into a bootable USB installer. You pick your USB drive, select the ISO, choose the partition scheme that matches your PC, and select START. Then you boot the PC from the USB drive and install Windows 10. This guide covers each step and the settings that most often cause problems.
Note: Windows 10 reached end of support on October 14, 2025. Consumer Extended Security Updates (ESU) now run until October 12, 2027. These steps still work on Windows 10, but upgrading to Windows 11 is the long-term way to keep getting security fixes.
What you need
- A USB flash drive of at least 8 GB. Rufus erases everything on it.
- A Windows 10 ISO file. Get it from Microsoft’s Download Windows 10 page, or let Rufus download it for you (see Step 2).
- Rufus, downloaded only from the official site, rufus.ie. The portable version runs without installing anything.
- A Windows 10 license, if the PC has never run an activated copy of Windows 10. PCs that were activated before reactivate automatically.
Step 1: Open Rufus and pick the USB drive
- Plug in the USB drive and copy off anything you want to keep.
- Run Rufus. Allow it to check for updates if asked.
- Under Device, choose your USB drive. Check the size and name carefully so you do not pick an external hard drive by mistake.
Step 2: Select the Windows 10 ISO
- Under Boot selection, make sure Disk or ISO image is chosen.
- Select SELECT and browse to your Windows 10 ISO.
No ISO yet? Select the small arrow next to SELECT, switch it to DOWNLOAD, and Rufus can fetch an official Windows ISO from Microsoft’s servers. Pick Windows 10, the latest release (22H2), the edition, language, and architecture (x64 for almost all modern PCs).
Step 3: Choose the right partition scheme
This setting decides whether the USB boots on your PC:
- GPT with target system UEFI (non CSM): choose this for most PCs made since about 2012. It is required if you want Secure Boot.
- MBR with target system BIOS (or UEFI-CSM): choose this for older PCs with a legacy BIOS, or if the GPT drive does not show up in the boot menu.
Not sure? On the PC you are installing on, if Windows still runs, press Windows + R, type msinfo32, and check BIOS Mode. “UEFI” means use GPT; “Legacy” means use MBR.
Step 4: Leave the format options at their defaults
Rufus fills in the volume label, file system, and cluster size based on the ISO. For Windows ISOs it normally uses NTFS, because one of the installation files is larger than the 4 GB limit of FAT32. You do not need to change these.
Step 5: Create the USB
- Select START.
- Rufus may show a Windows User Experience window with optional customizations. Check only the options you understand, or leave them all unchecked for a standard installer, then select OK.
- Confirm the warning that all data on the drive will be destroyed.
- Wait for the progress bar to fill and the status to show READY. This usually takes 5 to 20 minutes depending on the USB drive. Then select CLOSE.
Step 6: Boot from the USB and install Windows 10
- Plug the USB into the target PC and restart it.
- Press the boot menu key as the PC starts. F12, F11, F9, F8, and Esc are common; the startup screen often shows which key to use.
- Choose the USB drive. If you made a GPT/UEFI drive, pick the entry that starts with “UEFI”.
- In Windows Setup, choose your language and select Install now.
- Enter a product key, or select I don’t have a product key if the PC was activated before.
- Choose Custom: Install Windows only (advanced) for a clean install. Select the drive and follow the prompts. Deleting partitions erases their data, so be sure your backup is complete.
- When the PC restarts, remove the USB drive so it does not boot into Setup again, and finish the setup screens.
For a clean install on a blank drive, also see installing Windows 10 on a new hard drive. After Windows starts, our Windows 10 setup guide walks through the first-run settings.
Troubleshooting
- The USB doesn’t appear in the boot menu: remake it with the other partition scheme, or check the firmware settings for USB boot and the boot order.
- “Secure Boot violation” or the drive won’t start with Secure Boot on: make sure you are using the current Rufus version and a GPT/UEFI drive. As a last resort, temporarily turn off Secure Boot in the firmware settings and turn it back on after installing.
- Setup says a driver is missing or can’t see the drive: try a USB 2.0 port, or load the storage driver from your PC maker’s support site.
- Rufus doesn’t list your drive: it hides large external hard drives by default. Use a flash drive instead.
Other ways to make a Windows 10 USB
Microsoft’s own Media Creation Tool also builds a USB installer, with fewer choices. See how to make a bootable Windows 10 USB, or use Command Prompt if you can’t run extra software. Installing Windows 11 instead? See how to use Rufus to install Windows 11.
Frequently asked questions
Is Rufus safe?
Yes, when downloaded from rufus.ie. It is open source and widely used. Avoid copies from download mirror sites.
Does Rufus work on a Mac?
No. Rufus runs only on Windows. On a Mac, see our guide to creating a Windows 10 bootable USB on Mac.
Can I use the USB drive for files afterward?
Yes. Reformat it in File Explorer when you no longer need the installer.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.