The rules are set by Microsoft not Dell. MS says you have to buy the Pro license from the Store to upgrade unless you have an unused retail (not OEM) version of Pro that has an activation code. If you do not need to enter a domain at work or do not need Bitlocker--stay with the OS you have. You already paid for it. Here are the rules

https://support.microsoft.com/en-us/help/12384/windows-10-upgrading-home-to-pro 

If you install the retail version it has to be a clean custom installation where you lose everything on the windows partition when you delete it. It is a full version of windows not an upgrade. 

Here is a complete list of the differences between Windows 10 Home and Pro: https://gadgets.ndtv.com/laptops/features/windows-10-home-vs-windows-10-pro-differences-new-features-718532

I think I'll stick with the Home version.

My systems well, and I do not want to do a reinstall.

Thanks,

Bill

Have you tried just changing the License key to see if that might work? If you have the retail Win 10 Pro, it might

I have never done that personally, I normally buy the upgrade to Pro and use it, which is just a license change.

not giving an opinion but  ---

on EBay you can get a Win10 Pro licence key for $5 - $6.  i haven't tried the licence key thing, but i did buy and use a full install DVD and used it.  in my case my machine was a Home Edition and i stuck with it,

EBay you can get a Win10 Pro licence key for $5 - $6.

This is obviously a scam.

Home costs $109 and Pro costs $199. 

how can it be a scam?  i used it, with success.  i'd give you a link to the one i used, but that might be against Dell policy. 

I did a fresh install, formatting my old installation from the partition but I still arrived home version

It’s commendable on Microsoft’s front to pack Windows 10 Home with all the core features, considering it’s the basic version. Windows 10 Home should work fine if you just care about the new attractive features like Cortana, Timeline, Windows Hello, etc. Microsoft has also added some security features in the Home edition like Microsoft Passport, device encryption, and more.

Coming to Windows 10 Pro, it packs all the core features and along with that, it brings some very advanced business aimed features like Windows Store & Update for Business, Azure Active Directory, BitLocker, Enterprise Data Protection and more. 
Maybe this will clear your doubts... 

And for upgrading from home to Pro, you'll need to purchase the Pro version. Check with time if Microsoft is providing some offers for upgrading your windows.