Save CU update?

Of course- just as with previous builds.
Download Windows 10 ISO File - Windows 10 Installation Upgrade Tutorials

Then you can create a bootable repair disk, or use it to install multiple times, and as a source for an in-place upgrade repair install if needed.

dalchina said:

Of course- just as with previous builds.
Download Windows 10 ISO File - Windows 10 Installation Upgrade Tutorials

Then you can create a bootable repair disk, or use it to install multiple times, and as a source for an in-place upgrade repair install if needed.

Sure if OP downloads iso, but reading his post I think he meant saving a file when downloaded by Windows Update which is more or less impossible.

I assumed the original question was simply somewhat imprecise. Hopefully the answers will provide enough information.

(Interestingly there is a tutorial about creating an ISO from Windows as installed...)