It's always been that MS upgrade versions provide only new equivalent to the old. You can't go from a Home version to a Pro or vise versa. Keep in mind that some features of Windows 7 have been stripped out of Windows 10 and particularly in regards to media codecs and some of the old games. You'll lose the DVD player unless you beat the deadline to install the free version.
I am currently running Win7Pro. I first heard that if I upgrade to Win10 it would be the pro version since I have Win7 Pro. All this time since last July, I have yet to see anything about this subject. I am still wondering, if I choose to upgrade, will I get Win10-Pro. Has anyone done this?