In the initial phases I didn't get the updates needed to begin the Win10 upgrade process. They only started about a week or so ago. What I have found is that there are actually two or more prerequisite updates needed before the nags begin. The two I know of are KB2952664 and KB3035583. The first claims to be one that checks your system for compatibility and the other (xxxx583) is apparently the one that lands in your notification area and generates the Win10 icon. As I understand it, these must be found and uninstalled. They will return later, however. When this happens, you uncheck the box to install them, do a right click and hide them. Initially, I uninstalled KB3035553, did an update search and it came back. I hid the update and it was no longer visible. However, it did come back. This time, I uninstalled KB3035583 and hid the update when it returned. It's now a waiting game and I'll see what happens but you might also try the same. BTW, I did find this information using a google search and it does appear that the folks who try to buck the upgrade nag are in for a fight.