The most legitimate method is to buy Win 10 64bit prof, single user license in a box, use a brand new hard drive, at least a 2TB or partitions in 2 TB (500GB will also work) and format it from scratch and custom load the OS.
Do NOT upload the default Bing or allow Win10 to send out info to help you out.
BTW, the default upload of win10 will auto matically upload a Cortana window on your taskbar. There are ways of getting rid of it, but they also deleted the normal slide bars to turn off that option.
Once Bing is installed on the machine and Cortana, it is nearly impossible to get rid of all the back doors on the system.
If you don’t care, by a new machine with it preloaded, but if you see Bing on it, it will be virutally impossible to remove it. The OS isn’t that well documented on what’s going on within it. Practical application, its a great OS, but even MS doesn’t know all the functionality and vulnerabilities.
What is Bing?