How to to do a clean install of Windows 11 using an ISO instead of upgrading from Windows 10.
Many people are wanting to test out the latest version of windows 11 on an old or experimental PC without having to install it over a prior operating system, and in order to do that you will need a Windows 11 ISO file that you can boot from and use to do a clean install.
There are a few ways to get one. You can download a Windows 11 ISO directly from Microsoft (although it may not be the latest build), or you could download the files from Microsoft’s update servers and build a custom ISO that is up to date. You can then use the ISO file to create a bootable installation USB Flash drive which may allow you to install Windows 11 on a computer that doesn’t meet the new operating system’s minimum requirements (4GB of RAM, TPM, Secure Boot).
If your a member of the Windows Insider program then the easiest way to get a Windows 11 ISO is by downloading one directly from Microsoft, if not you can always obtain one using uupdump.net, which gives you a script you can use to download the files from Microsoft then convert them into an ISO file….
Once you have a working ISO you will then need to burn it to an optical disk (DVD) or install it on a bootable flash drive.
Creating a bootable flash drive for Windows 11 can be a bit of a problem, this is because the main installation file is more than 4GB so standard programs for creating bootable flash drives such as Rufus or UNetbootin will create an NTFS-formatted boot drive which means that you will have to disable Secure Boot (in your BIOS) in order to boot from it, and as Windows 11 requires Secure Boot the installer may tell you that your computer does not meet the requirements.
Fortunately there is a way round this by using Disk Management to create a USB Flash drive that can both hold your files and boot on a Secure Boot-enabled PC.
Insert your USB Flash drive (min 8GB required)
Go to Disk Management (Right Click on the Windows Logo)
Delete all the partitions on the USB drive (Right Click and select “Delete Volume)
Next. Create a 1GB partition and format it as FAT32 by right clicking on the unallocated space and selecting New Simple Volume (this will be the partition that contains the files you need to boot from)
Then Create a second partition by clicking on the remaining unallocated space and format it as NTFS
Mount the ISO file by right clicking on the ISO and selecting Mount
Copy all the files and folders, except the “Sources” folder, from the ISO to the FAT32 partition
Create “New Folder” on the USB drive’s FAT32 partition and name it “sources”
Then copy the “boot.wim” file from the original “sources” folder into it
Finally copy “ALL” of the files and folders from the ISO into the NTFS partition of the USB drive.
Now you have a USB Flash drive that can boot up a computer with Secure Boot enabled.
