Is AU required before Insalling CU

I haven't seen this particular question come up.
Will CU run with out the AU already installed?
I have one business computer that has some pretty important programing I didn't install the AU in the beginning because of all the issues. And then I just didn't need it for anything. This CU update seems to be installing with out issues so this might be the time for me to bring this busiess computer up to date. I really don't want to run the AU from updates. I didn't create a Install USB before the switch the ISO to CU?

Yes I do have am Image.
Seems until windows 10 any major upgrade/Update accounted for all the previous updates.
So I just thought I'd ask, seems to me it should just install. My other Z97 Machine upgraded to CU with out any issues at all. Classic Shell and 8gadegt ran auto update before they ran this computer had the AU on it so that's why I asked
Thanks for the reply

Your link leads to the MCT which is now having CU update included. I plan to use that to do the CU upgrade. I don't trust the update process for these major upgrades.

"I don't trust the update process for these major upgrades. "

My feelings exactly ! Should be able to go directly to 1703 from 1507, as the MCT is essentially an install iso/dvd of the the newest OS, independent of what is on the device now.

Well I'll take that back, I checked on the Z97 that I thought I had Installed the CU, turns out MCT created on that workstation saw that I wasn't up to date and installed the latest version 1607. So I'm betting that the other Z97 which is still on 1511 is only going to 1607

Did you actually download a new MCT and use the most up to date one? MCT do not automatically download the latest version of Windows 10. They will always download the version of Windows 10 they were meant for at the time of download.

A MCT downloaded 2 months ago will continue to retrieve and install ver 1607. A MCT downloaded today will only retrieve and install ver 1703, even a year from now after the next major upgrade is released.

Yes now this Z97 Pro computer did upgrade from 511 to 1703 had a couple of hick ups along the way but at the end I'm running fine on 1703 all my important software is working with out issues.
So My other Z97 computer only updated to 1607 latest updates, I have rerun MCT and currently running the upgrade again, I have no Idea why 1703 did not install the first time?

So my Office workstation has now create a USB using MCT for the 2nd time , and after install I am still on 1607?? No error messages during install, Well 2 out of 3 ain't bad lol
Tempted to use the USB I made for and on my Front Desk workstation

Ok problem solved. for my Office computer I was using a desktop link, which was linked to the 1607 Build. Downloaded a new MCT with the 1703 Build and done this Office computer is up and running with out issues.

So the answer to my original question is the AU update required to install the CU upgrade: The answer is no, you don't have to have the AU installed, you can go direct to the 1703 CU Build from 1511 Build.

Thanks everyone for you replies and advice.