Microsoft’s big plan to have Windows 10 on a billion devices in just a few years starts at the end of this month, when – on July 29 – it becomes available for free, zip, zero, zilch. But if you’re like us here at PC Mike, the soon-to-be available free operating system raised more questions than answers. So we dug into it and bring you what we learned about Windows 10 in this episode of the PC Mike podcast. Among other things, we discuss: What are you supposed to do with that “Get Windows 10” app icon that probably appeared recently in your toolbar? Why do you need to “reserve”…