Is there any way to back out at this point before I reboot? I would like to hold off for a while until I am sure a few legacy applications can handle it.
Click Start, type: view installed updates. Hit Enter, look through the list for the KB3035583 update. Right click it and click Uninstall
If I change my mind, can I cancel my reservation? Yes, you can cancel your reservation at any time prior to installing Windows 10. Here’s how: Right click on the Get Windows 10 App or Windows icon located in right end of the taskbar. Select “Check your upgrade status” Select “Cancel reservation” http://www.microsoft.com/en-us/windows/windows-10-faq