Windows 10: RTM Windows 10 Retail License

We are a computer store selling and servicing computers for individuals and businesses. Can we buy RTM Win 10 Pro Retail keys on line and resell them, we have found that the key installs and activates, however we are unsure if this is legal.

:)

 

Upgrading to Win 10 RTM Professional Retail

What is Win 10 RTM Professional Retail? How is it different from Windows 10 Home? Will you suggest me to change my laptop product key from Windows 10 Home to Windows 10 RTM Professional Retail? What
benefits would I get in Windows 10 RTM Professional Retail?

 

Windows 10 upgrade license

Hello guys,

I have 1 license of WIndows 8.1 FPP/retail license. I want to upgrade to WIndows 10, but I one thing is unclear to me.
If I upgrade, will WIndows 10 license be retail or it will "turn" into some sort of OEM license?

I ask this because I upgrade my PC, you know, more memory, replace HDD, and I intend to upgrade the MB and CPU to Kaby Lake platform sometime in the future, (and of course sell the replaced hardware)
This thing is not clearly mentioned anywhere.

Thank you.

 

Upgrading to Win 10 RTM Professional Retail

My Laptop is preinstalled with Windows 10 Home already. I wanna experience win 10 RTM Professional Retail. I've a product key for win 10 RTM Professional Retail. If I change the product key then will I be able to come back to windows 10 Home?