Download any Windows 10 version ISO from Microsoft

Steve C said:

I always use the Microsoft Windows and Office ISO Download Tool from heidoc.net

The GitHub tool is useful if you need an ISO that contains an install.esd. An esd means you can make a bootable Fat32 USB using Option Four in this tutorial.
Create Bootable USB Flash Drive to Install Windows 10

Steve C said:

What happens if you upgrade using the heidoc.net tool (no insall.esd) then use Windows Update for the next feature update - do yo get install.esd then?

A feature update through Windows Update works quite differently from using an ISO to perform the feature update, though the OS you end up with will be identical.


An ISO contains the full set of files for the new version (whether as an install.wim or install.esd) and is known as a 'canonical build'. Windows Update uses the Unified Update Platform (UUP) and just downloads the parts of the OS that have changed since the previous build. That may be whole files, or delta patches to apply to your existing system files to construct the new ones. There is no install.esd or .wim downloaded, so there's nothing you can keep.

The advantage is that the download to perform a feature update can be up to 35% smaller than the full download of the canonical build. The disadvantage is that once the download is complete there's a lot of processing to apply the delta patches. This can make a feature update via windows update slower than one done using an ISO, particularly on older slower machines.

Microsoft said:

...one of the biggest benefits UUP brings to our customers is a reduction in download size of build updates on PCs...

A differential download package contains only the changes that have been made since the last time you updated your device, rather than a full build. Differential download packages rely on re-using files on your current OS to reconstruct the newer OS. This could include copying files as-is that have not changed between builds, or it could involve applying “binary deltas”� or “diffs”� to old files to generate newer files. Differential download packages are smaller and can take a shorter amount of time to download.

For a full build, we refer to this as a canonical download package. It is a self-contained update that contains all files for the update, and does not rely on any files on your device. Canonical download packages tend to be larger in size and may take longer to download.

An update on Unified Update Platform (UUP) for Windows 10

Steve C said:

Very useful thanks. I'll probably use the ISO file in future

For the H1 feature updates that would be quicker than using windows update, but for the H2 minor feature updates then windows update is by far the fastest way, it juat downloads a small enablement package that installs like a CU. There's no windows.old created when using the enablement package method either.