Last night Microsoft sent KB 3035583 down the Automatic Update chute. Again.
The patch is listed as recommended, but not a security patch, for Windows 7 and 8.1 systems. Depending on your Windows Update settings (and sometimes, I think, the phase of the moon), the patch will probably appear among your "Important" patches, and probably won't have its box checked. If that's what you see on your PC, KB 3035583 won't install unless you check the box and run Windows Update.
As we've seen in the past, though, sometimes those unchecked patches suddenly get checked and Windows Update proceeds with the dirty deed. All the more reason to set Windows Update to "Notify but don't download."
Your best bet right now, if you have Windows 7 or 8.1 and don't want to upgrade to Windows 10 just yet -- remember, you have until July 28, 2016 to upgrade for free -- is to cut KB 3035583 off at the knees. The easiest way to do that is by running GWX Control Panel.
Microsoft has provided no changelog, of course, and no indication what this version of Get Windows 10 does that's any different from the five previous versions.
I'm still looking for a single example of a KB patch, other than a security patch, released in 2015 for Windows 7 or 8.1 that does something worthwhile for Win7 and 8.1 customers. (Time zone changes in Eastern Europe don't count.) Can you recall one?