Just a quick reminder if you're running 7/8 & haven't run one of the tools to turn off the coerced upgrade to 10, be careful.
I purposely have not run the tools in a couple of win7 VMs so I might spot new activity -- today I recorded new files added to the C:\Windows\ System32\ GWX folder, along with new scheduled tasks in the registry with timer entries etc.
I have not seen this, but there are reports of upgrade to 10 pop-ups that do not have a cancel or decline button, & closing that pop-up window starts the upgrade process. Now there is some debate whether this was as it seemed, or if users already clicked OK to schedule the upgrade, but regardless, be careful.