I previously wrote a guide to download Windows 10 directly from Microsoft and also check the hashes to confirm they are original/legit copies of Windows. With Rufus you are able to do pretty much the same step, but quicker so I’ve always been thinking of writing it up. Having issues with legacy and UEFI systems not reading the bootable USB drive, I thought I can combine the two.
There are other guides out there so I think I do not need to go into deep detail, you can always go check them out if you get stuck (links down below), however I simply wanted to point out the key things that may cause issues.
Once you start Rufus rather than selecting an ISO file (windows you’ve already got downloaded) instead use the drop down menu and click “DOWNLOAD” then literally click the “DOWNLOAD” button again so it pops up the menu to download your preferred version. Do this with the latest version of Rufus or make sure to update Rufus using the cog settings at the very bottom of the program.
After that I prefer to download via the link and save the ISO for another time. I then repeat usual process of selecting an ISO and the important parts here are now loading up the Partition scheme as “MBR” pressing ALT+E to ensure the target system is BIOS or UEFI.
I have seen people select the file system as FAT32, but if you do that with the latest windows with file sizes larger than 4gb you will have issues, because I can confirm for example in Windows 11 and also Windows 10 21H1 you will have files larger than 4 GB’s within the installation so stick to NTFS.
Other guides
https://rufus.ie/en/
https://www.windowscentral.com/how-create-windows-10-usb-bootable-media-uefi-support
Update 2021/11/21: Typo corrected.